, Comprehensive Signal & Communication Services September 23, 2004 Mr. Jim Pierce City of Addison Asst City Engineer 16801 W. Grove Drive PO Box 9010 Addison, TX 75001 Re: Federal Highway
Administration Interim Approval of the Automated Hom System Dear Mr. Pierce: Railroad Controls Limited is pleased to announce that the Federal Highway Administration (FHWA) has just
issued interim approval for the use of the Wayside Horn System (Automated Horn System.) Under the Federal Railroad Administration's Interim Final Rule on the Use of Locomotive Horns
at HighwayRail Grade Crossings, if a Wayside Horn System (AHS) is considered a traffic control device by the FHWA, then it must also be included in the Manual on Uniform Traffic Control
Devices (MUTCD). The FHWA has determined the Wayside Horn System is a traffic control device, and has granted interim approval until it can be included in the MUTCD. The advantage of
this inclusion is it will no longer be required that the Wayside Horn be installed on an Experimentation Basis outlined in section 1A 10 of the MUTCD. The FHWA also provides additional
guidance for the installation of the Wayside Horn. If you would like additional information in this regard, please feel free to contact me at (817) 820-6347, or if you would like to
view the FHWA document online please visit our website at www.railroadcontrols.com and click on the FHW,,\ approval link. Best regards, RAILROAD CONTROLS LIMITED /!/1iZ;z_Robert Albritton
National Sales Manager 7471 Benbrook Parkway· Benbrook, TX 76126.817-820-6300· Fax 817-820-6340 
Memorandum Electronic Mail Subject: INFORMATION: MUTCD -Interim Approval for Use ofthe Wayside Horn System Date: August 2, 2004 From: Regina S. McElroy IslRegina McElroy Director, Office
of Transportation Operations Reply to Attn. of: H OTO-I To: A. George Ostensen, Associate Administrator for Safety Division Administrators Resource Center Directors Federal Lands Highway
Division Offices Purpose: The purpose of this memorandum is to issue an Interim Approval for the optional use ofwayside horn system (WHS) at highway-rail grade crossings. Background
Summary: The use oftrain horns provides an audible indication to road users of the approach of a train at a highway-rail grade crossing. Although this device provides a safety benefit
to the road user, the community in close proximity to the railroad crossing can be subject to the sound impact of the train horn, which can occur any time ofthe day or night. To mitigate
this problem, the Federal Railroad Administration (FRA) and the Federal Highway Administration ((FHWA) Office of Safety have monitored over the past 10 years the development and implementation
of a WHS. The WHS is located at the crossing and directed at oncoming motorists, which (1) simulates the sound and pattern of a train horn; (2) provides similar (or safer) response from
road users, and (3) minimizes the audible impact on individuals located near the crossing (the WHS theory of operations is attached to this memo). Additionally, the FRA has documented
an Interim Final Rule, entitled "Use ofLoccmotive Horns Highway-Rail Grade Crossings" (published in the Federal Register at 68 FR 70586 on December 18,2003), which provides the use of
train horns at public crossings and the use ofthe WHS. Interim Approval for the WHS is hereby granted based on FRA's Interim Final Rule, as well as current deployments and evaluations.
Provisions for the WHS: Option: The wayside horn system may be installed in accordance with part 222 oftitle 49 ofthe Code of Federal Regulations (49 CFR) to provide directional audible
warning at highway-rail grade crossings equipped with active traffic control devices consisting of, at a minimum, flashing lights and gates. 
) Standard: The wayside hom system for use at active highway-rail grade crossings shall conform to the FRA's requirements for the wayside hom prescribed in Part 222 of 49 CFR, Appendix
E. As a minimum, the wayside hom system shall be installed for each roadway approach to the highway-rail grade crossing to provide audible warning. . Guidance: A diagnostic review should
be conducted by a diagnostic team to determine the optimal placement ofthe wayside hom system and to ensure the correct and most effective use of the system. The diagnostic team should
be composed ofrailroad personnel, public safety or law enforcement, engineering personnel from the public agency with the responsibility for the roadway that crosses the railroad, and
other concerned parties. The highway agency or authority with jurisdiction should consider the inclusion ofremote health (i.e., status) monitoring capable of automatically notifYing
maintenance personnel when anomalies have occurred within the system. The wayside hom system should should comply with the same lateral clearance and roadside safety features described
in the MUTCD Section 8D.O I. When a wayside hom is mounted on a separate pole assembly, it should be installed no closer than 4.6m (15 ft) from the centerline of the nearest track. In
addition, a wayside hom should be located where the device will have optimal results, and not obstruct the motorists' line of sight to the flashing-light signals. Conditions of Interim
Approval: Jurisdictions wishing to install the WHS under this Interim Approval ofWHS must meet the following 􀁣􀁯􀁮􀁤􀁩􀁾􀁯􀁮􀁳􀀺􀀠I. The use of WHS shall comply with provisions described
in the above Provisions jor the WHS. 2. A written request shall be submitted to the Director ofthe Office ofTransportation Operations acknowledging the jurisdiction's agreement to comply
with MUTCD Section IA.IO, item F. The request must also state the location(s) where the device will be used. 3. Jurisdictions shall be responsible to notif'y the FRA of installation
of WHS as required in 49 CFR 222, and shall inform the FHWA ofsuch notification in their written request to FHWA for interim approvat Any questions concerning this Interim Approval should
be directed to Ms. Guan Xu at guan.xu@fbwa.dot.govorby telephone at 202-366-5892. 
References: I. 49 CFR Part 222 2. Wayside Hom System Interim Approval Request from A. George Ostensen 3. 2003 MUTCD Section IA.I0 Attachments: Theory ofWHS Operations WHS Research Summary

Theory ofWHS Operations The WHS system operates in conjunction with train operations. Under normal conditions at an active crossing, the train's locomotive will normally engage its horn
approximately one-quarter ofa mile from the crossing. The horn will continue to sound severa! additional times until the train enters the crossing. The WHS focuses the sound ofthe horn
to the road user, thereby eliminating the requirement that the locomotive sound its horn from such a far distance (currently trains typically sound their horns a quarter-mile from the
crossing). The WHS is located at the crossing on a pole in close proximity to the Crossbuck. Once the train has approached the crossing where the train horn would begin to blow its horn,
the WHS is engaged. The WHS emits a digitized horn sound that is directed in the path ofthe user. Based on the location and orientation of the WHS, significant sound abatement is created
for the general area surrounding the crossing, and provides a warning to road users approaching the crossing. Additionally, a visual signal is placed along the rail corridor's right-of-way
in advance ofthe crossing to notify the locomotive engineer that the WHS is operating. Pursuant to FRA's Interim Final Rule (49 CFR 222, Appendix E), the locomotive engineer has the
right to engage the onboard train horn, when it is determined that it is in the best interest in safety (for both the road user and the train). WHS Research Summary The effectiveness
of the WHS has been studied and documented over 10 years at active highway-rail grade crossings, and has shown substantial benefits to such grade crossings. The studies were conducted
by agencies/organizations such as the FRA, Volpe Center; Northwestern University; City ofRichardson, Texas; Association ofAmerican Railroads; Iowa State University, and Texas Transportation
Institute. Key conclusions of the studies include: • The studies showed significant reduction (more than 50 percent) in the number of motorists' violations ofthe crossing gates as compared
compared to the baseline data collected with the train horns sounding. • The WHS was well accepted by both motorists and locomotive engineers. • The WHS gives equal or greater audible
notification as compared to train horns. • The WHS provides a good balance between providing adequate advance notification to road users and minimizing community noise levels. • The
WHS appears to continue to be an effective alternative to the locomotive horn. 
I 􀁒􀁴􀀬􀁊􀁾􀁾􀁁􀁉􀁾􀀠, if-It;;-oi'f City packs using train gates ',-, ContinudfrtymEageis wayside barns thattake the pJaceof the train 'W!ristJe andfucu:, the sound at the intersection,
build barriers in the roadway medians to prevent motorists from golpg around the gate or install gates ori both sides ofthe rail in botl! directions. to,prevent motorists from goingaround
RichardSon bas' 10 'railroad crossings where the ,quiet 'lOues couldbe implemented 'rhe city installed a wayside born in November2000 wbere the• Kansas City Southern Railroad crosses
Custer 1'arkway. The quiet zone idea was so fresb back then that former Vice President Dan Quayle visited Richardson for a televisiOn DCWsspOt.' "At the time, we were cutting edge,"
MayorGaIy Slagelsaid. , But now that the new railroad rules are out, the cOuncil said ,the city should go with the more ec0nomical median ba.rtiers. The city also bas a test site for
this techniCllie, in place at the Cotton Belt and custer Road since 1996. City transportation officials estimate it would cost between $120,000 and $300,000 to put in median barriers
citywide, comparedwith$270,000to $360,000 for wayside borns. The gates in all directions, called quad gatlis, are fur more expensive, costing as muchas $150,000 each: The citybas $240,018
in acapital projects budget fur quiet zone construction. More moneY will probably be needed to finisb the project,' transportation director WalterRagsdale said. Robert Budzinski bas
pushed fur a quiet zone near bis neighborhood, south of Centennial Boulevard. The city installed an experimental way.;ide hom, He collected signatures on a petition opposing v,"\YSidehoms
after thetestsite was installed ,on Custer Parkway. His neighborhood bas three crossings that couldbequietzones. City tests showed that noise levels in the neighborhood deereased with
the ""\YSide horn, but Mr.. Gates WiIh median barriers are being endorsed instead of ' WlIlTIing horns for Ricb.a:rdson train crossings. This gate is nearthe Bush Turnpike and Custer
Road. Budzinski said that the decrease was not significant and that those who live closest to the horn experience morenoise. "fm vel)' happy the council bas made a decision not only
to save moneY but to introduce quiet into 􀁴􀁨􀁥􀁮􀁥􀁩􀁧􀁨􀁢􀁯􀁲􀁨􀁯􀁯􀁤􀁳􀀬􀁾􀁨􀁥􀁳􀁡􀁩􀁤􀀮􀀠The median barriers run between traffic lanes near the track. TheY mostbe at least six inches
tall andlOOfeetlong, Mr. Ragsdale said this could pose a problem at three crossings. including the one that has a wayside hom now. Barriers that length would impede turns at Ahna Road
and the Rush Thrnpike and into,alleys at two erossiitgs in the Canyon Creekneighborhood. , Mr. Ragsdale said a consultant v.<Juld prepare recommendations and analyne costs for each of
the proposedquietzones.includingthe three problem ones. He said meetings would be scheduled with homeownersto get input. John Davis lives on Big Hom Drive aridwould 10liC easy aeeessto
his aIlCY ifa barrier were installed. He said thetrade-offwouldnol be , t t r l, " worth it. "Ifthat's tbe price we have to payfor a quiet zone, I1l keeptbe noisyzone,"hesaid. 
, " I n h d e r t o e [" l-1"fY COUNCIL •TraIn' gates ". trump horns 'Alternative to noisy warnings endorsed as cost-effective, quiet, By SARAH POST , ' StaifWriter A 1:!'ain's mournful
whistle in the night is not, romantk, just ' noisy, those who live near the track say. , Richardson has been looking at ways to provide quiet zones whe", neighborhoods and tracks intersect
for several years. Monday, the ' city decided to abandon wayside horns fixed horns intended to ' more narrowly focus the sound in favorofnewer, cneaper methods. Instead, the city will
instlllI, gates with mcdlan barriers, an alternative recently approved by the Federal RailroadAdministration. Mayor Pro Tern John Murphy said Monday that he was glad they did not rush
to use the wayside hom technology. "I always thought wayside horn and quiet zone was an oxymoron," he said The administration passed rUles in December in response to many conununities
that have pressed fur relieffrom train whistle noise. Officials providedscveral exceptions to the' 􀁲􀁥􀁱􀁵􀁩􀁲􀁥􀁭􀁾􀁮􀁴􀀠that trains blast horns at all road crossings. including those
with gates. Under the new rules, cities wisbingto ban whistles mayinstllll See CITY Page lIS 
AUTOMATED AHST..􀁲􀁮􀁄􀁲􀁮􀁾􀀠SYSTEM Automated Horn System Ames, fA The Technology Providing Motorists the Warning They Need WhatisAHS? AHS, the Automated Horn System, is an innovative
railroad signaling device that significantly improves safety for motorists and pedestrians at railroad-highway grade crossings while dramatically reducing the amount of noise pollution
created by train horns along rail corridors in populated areas. Increases Audible Warning by21% Train at 1/4 Mile Distance Train Horn AHS 50' 78.0 dB 98.9 dB 100' 􀀷􀀳􀀮􀁾􀀠dB 93.7 dB
200' 75.0 dB 84.9 dB 300' 67.8 dB 795 dB 400' 64.0 dB 73.7 dB AHS is a stationary hom system activated by the railroad-highway grade crossing warning system. The Automated Horn System
is mounted at the crossing, rather than on the locomotive, to deliver a longer, louder, more consistent audible warning to motorists and pedestrians while eliminating noise pollution
in neighborhoods for more tban one-half (1/2) mile along the rail corridor. AHS is designed to sound like a train hom. The tone modules in the Automated Hom System horns were digitally
recorded from an actual locomotive hom. Upon receipt of the signal from the railroad's track circuit warning system AHS mimics the train hom warning by cycling through the standard railroad
whistle pattern until the train reaches the crossing. Once the train has entered the crossing AHS stops sounding its hom. A confirmation signal notifies the locomotive engineer that
the Automated Horn System is functioning properly. When the locomotive engineer sees that the confirmation signal is flashing, he will not be required to sound his hom unless he detects
an unsafe condition at the grade crossing. Coordination with the railroad operating company is essential since the Automated Horn System is directly connected to the railroad's crossing
signal-warning system. Additi01!ally, the railroad operating company must issue instructions to their train crews regarding the sounding or non-sounding ofthe train's hom. Automated
Horn System• Phone: (817) 820-6300 Fax: (817) 820-6340 A Division ofRailroad Controls LP 7471 Benbrook Parkway Benbrook, IX 76126 Website: www.railroadcontrols.com/ah!.i 􀁁􀁵􀁦􀁴􀁬􀁭􀁾􀁬􀁴􀁤􀀠Horn
􀁓􀁽􀀧􀁾􀀨􀁥􀁭􀀠CAIlSl is 11 rCIl-(sltred 􀁲􀁲􀁡􀁤􀁣􀁭􀁾􀁲􀁫􀀠or 􀁦􀁬􀀬􀁊􀁦􀁬􀁲􀀨􀁬􀁾􀀨􀁉􀀠􀁃􀁯􀁮􀀨􀁲􀁯􀁬􀁾􀀠Lilniled \rs r.thrttl"f!i1nl ; \..' 
AHS Research The Automated Horn System has been studied since J995. The initial study was conducted by John A. Volpe National Transportation Systems Center for the United States Department
of Transportation. Since then studies have been conducted by the Iowa Department of Transportation, Association of American Railroads, Texas Transportation Institute and the City ofRichardson,
TX. All the research to date has proven the Automated Horn System to he an effective solution for mitigating train horn without compromising driver safety. AHSnl Study Conclusions Ames,IA
"The safety evaluation suggests that the wayside horn will not result in behavior that puts the driver at increased risk compared to the use of the train horn. The frequency of violations
was lower for the _wayside horn than the train horn, while the time to collision and violation time was not statistically or practically different for either warning system." -Field
evaluation of a Wayside Hom at a Highway-Railroad Grade Crossing, by U.S. Department of Transportation Research and Special Programs Administration John A. Volpe National Transportation
Systems Center, June 1998 ""The wayside horn provided an equal or significantly louder audible warning at the point at which motorists most need the warning." -Automated Wayside Train
Horn Warning Svstem Evaluation, Prepared for: The City ofRichardson, Texas, Prepared by: PB Farradyne Inc., May 2001 Wayside borns are a viable alternative to locomotive horns for audible
warning at grade crossings. Wayside horns have the advantage of being closer to the motorist. In addition, they have a more focused radiation pattern and produce less community noise
exposure." -Wayside Hom Sound Radiation and Motorist Audibility Evaluation, Prepared for: Association of American Railroads, Prepared by: Mike Fann & Associates, May 2000 "For nearby
residents, the automated horn system greatly reduces the negative impacts resUlting from tbe loud train horns; the automated horns are well accepted by both motorists and locomotive
locomotive engineers; and the automated system appears to provide an equivalent level of safety at the crossings." -Evaluation of an Automated Horn Warning Sntcm at Three Highway-Railroad
Grade Crossings in Ames. Iowa, by Steve Gent, P.E. (Iowa DOT), Scott Logan, p.E.(eity of Ames Iowa), David Evans (Iowa State University), 1998 "The AHS appears to be, after almost 5
years of operation, an effective alternative to the locomotive horn at the Tenth Street crossing in Gering, Nebraska, with a violation rate no greater than that observed during pretest
monitoring." -A Safety Evaluation of the RCL Automated Horn System, by Stephen S. Roop, Ph.D. Texas Transportation Institute, May 2000 
Trespasser Warning for Bridge Approaches or Other Problem Areas Trespasser fatalities have recently exceeded fatalities at grade crossings annually. Although trespasser fatalities can
occw' anywhere on the railroad, there are typically problem areas, such as certain bridges, areas of high pedestrian traffic, near schools where close calls with trespassers are routine.
The Automated Horn System provides audible wanling far enough in advance of the trains arrival to alert trespassers of the trains approach. The Technology The Automated Horn System,
in this application, consists of a horn, or multiple horns, focused on the area requiring trespasser warning. AHS utilizes standard train detection c:irc:uitry 10 activate tbe system.
Wben activated, tbe born sounds a series of sbort blasts designed to sound like a train born. If the hom or any other AHS component fuils to operate properly, a cellular RTU sends an
alann to allow for timely maintenance response. Improved Audible Warning for High Speed Rail Lines AHS AHS provides improved audible warning for drivers approaching crossings located
on high speed rail lines, As previously discussed, Railroad operating rules and individual state laws require the locomotive engineer to sound the hom 114 mile in advance of the crossing.
This results in reduced audible warning time for trains traveling SO mph or faster. Mundelein, IL Train Speed Warning TIme AHS Minimum For example, an 80-mph train would provide (mph)
(seconds) (seconds) approximately 11.3 seconds of audible warning, if the 50 18.0 20 driver could hear the hom when it was fIrst sounded 60 15.0 20 lI4 mile away. 70 12.9 20 AHS, when
installed at locations equipped with80 11.3 20 constant warning circuitry, provides a minimum of2090 10.0 20 seconds of warning regardless of tbe approaclling 100 9.0 20 train speed.
Since AHS is positioned at the crossing and focused on the roadway approach, tbe audible warning is louder tban tbe train born until tbe train is very near tbe crossing. 
Train Horn Decibel (dBA) ContonrMap Sound Comparison Train Horn vs. AHS Locomotive engineers are required by state law and the railroad's code of operating rules and regulations to sound
the train's horn 114 mile in advance of the crossing. They are also required to continue to sound the horn until the train arrives at the crossing. If the train horn is to be an effective
warning device for the motorist, it must provide a sound level capable of initiating a response from the driver when the train is approaching the crossing. Unfortunately the sound level
required to achieve that response and the location of the train relative to the crossing creates a significant noise impact on the community. The two noise footprints to the left depict
the area impacted by the sound ofthe train horn and AIlS respectively. The comparison of the train horn and AIlS shows a dramatic difference between the areas that are impacted at specific
decibel levels. By examining the 80 decibel contour on the two footprints it can be seen tbat Union PaciftC RR the area impacted by the AIlS is a fraction of the size of the 80 decibel
contour produced by the train horn. Automated Horn System Decibel (dBA) Contour Map How AHS Connects c:/power Supply Signal 􀁈􀁏􀁕􀁓􀁾􀀠􀁾to the Railroad U', , AIlS cOlmects with the
railroad's crossing AHS warning system in a manner sirnilar to traffic signal preemption connections. Typically AHS horns and control cabinets are mounted on their own pole assemblies.
The confinnation signal is attached to the top of one of the pole assemblies and must provide a clear line of sight to approaching trains from 114 rnile away. Power is typically provided
by the city. Automated Horn System• Phone: (317) 820·6300 7471 Benbrook Parkway A Division of RaiJroad Controls LP Fax: (817) 820·6340 Benbrook, TX 76126 Websilc: www.railroadcontrols.com/ahs
􀁁􀁕􀁬􀁯􀁭􀁾􀁬􀁾􀁤􀀠Hom Sy!>lcm (AUS, is l 􀀨􀁾􀀡􀀺􀁩􀁾􀁉􀁾􀁾􀁾􀁤􀀠􀀡􀁲􀀺􀀮􀁤􀁣􀁭􀁾􀁲􀁨􀀠of 􀁒􀀼􀀱􀁩􀁬􀁮􀀺􀁊􀁾􀁤􀀠􀁃􀁏􀁬􀁜􀁉􀁦􀁩􀀩􀁉􀁾􀀠Umiltd US hl.....􀁉􀀶􀀡􀁾􀀧􀀬􀁴􀁬􀀱􀀠
Evaluation of the Automated Wayside Hom System in Mundelein, Illinois Final Report Northwestern University Center for Public Safety 405 Church Street Evanston, IL January 2003 
Evaluation of the Automated Wayside Horn System in Mundelein, Ulinois Final Report Executive Summary Highway-Rail Crossing Safety and Train Horns At highway-rail grade crossings, the
train hom serves to warn motorists of a train's inunediate approach. The hom advises motorists, and other crossing users such as bicyclists and pedestrians, that entering on or crossing
the tracks would place them in imminent danger. However, because ofthe loudness and the wide angle of sound radiation, the hom can be an intrusive nuisance, especially in residential
areas near the tracks. As a result, an automated wayside hom system (A WHS) has been developed to provide an appropriate warning for those using the crossing, while not annoying those
living near the tracks. A study was carried out in Mundelein, Illinois, that compared the train hom with the A WHS. This report compares motorists' driving behavior at highway-rail crossings
and the sound levels ofthe two types ofhorns. The results from the evaluation show a significant 70% decrease in violations ofhighway-rail crossing law with the A WHS. Noise levels in
areas near the tracks decreased by up to 85%. Reducing the number of collisions between vehicles and trains has remained a priority in highway safety. During the past 10 years, collisions
nationally have decreased from 4,684 in 1992 to 3,064 in 2001 (Federal Railroad Administration). During this same period, all collisions with trains in Illinois remained fairly constant
with an average of232 per year. Even though there has been a general decrease nationally, these collisions remain the most severe type in terms ofproducing injuries and fatalities. Crossing
gates have the best record at reducing collisions, but a study done in Florida showed that even with crossing gates, a train hom still is needed The Federal Railroad Administration (FRA)
has proposed rules to require that horns be used at all crossings with few exceptions that are expensive to implement. The problem remains that the train hom, which, in Mundelein, starts
sounding approximately 17 seconds before the . train reaches the crossing, creates very high sound levels in adjoining areas. As a result ofthe need to alert motorists and at the same
time reduce the effect of sound on adjoining areas, Mundelein experimented with the use ofthe A WHS. The study reports the results ofthe evaluation ofthe A WHS. Northwestern University
Center for Public Safety Wayside Hom Evaluation -Final Report 1 
Conduct ofthe Study Five tasks were undertaken: site preparation, before and after motorist violation studies, before and after sound studies, quality·of·life studies, and surveys of
engineers and residents. At each of the three sites used for studying motorist behavior, utility poles were erected, and cameras and recording equipment installed. The recorders activated
when the warning signals activated, thereby recording what motorists did during the period the gates were descending and down before the train arrived. Drivers are considered to be taking
risks (and violating the Jaw) when they attempt to cross the tracks after the crossing gates start to descend. This action was measured by viewing videotapes made at each crossing during
the period the gates were activated. Data were taken during the period train horns were in use, then after a period of adaptation, when the wayside horn was in use. The violations were
divided into two classes: Technical violation where the driver crosses the tracks after the the gates start to descend but before the gate has been lowered sufficiently to block the
vehicle's passage, labeled a "Type I" violation, and Deliberate violation in which the driver either drives through or around the lowered gate. These are "Type 2" violations. Loudness
and sound characteristics were measured on approaches to several crossings with train horns in use and then after the wayside horns were activated. A comprehensive assessment of these
measures is contained in a separate report; this final report just summarizes the fmdings. Measures of quality·of-life derived from two sources: sound studies in residential yards and
a survey ofthe residents. The project team measured sound levels over 24·hour periods at nine locations throughout Mundelein. These measures were made dnring the period when train horns
were used and again after the wayside horns were placed in service. Comparisons included the average sound level in one-second periods, during the time that horns were sounded, and a
sound exposure level. The latter takes into account duration and allows direct comparison of sounds between different locations and over different periods. In addition, surveys were
sent to a sample ofresidents in Mundelein. The survey asked residents how they viewed the new hom system compared to the train horns. Several questions also were directed toward the
residents' views of changes in crossing safety. Finally, a survey was distributed to engineers from both the freight railroad (Canadian National) and commuter rei! (Metre). This survey
was modeled after the one nsed in Ames, Iowa, for a Northwestern University Center for Public Safety Wayside Horn Evaluation -Final Report 2 
similar evaluation. Itasked the engineers how they perceived the crossing safety before and after the wayside horns were activated. Evaluation of Changes in Crossing Violations From
the period September 8 through December 20, 2001, 10,392 gate activations were recorded on videotape at three crossings. During the second period of observations, April 12 through July
16, 2002, 9,112 activations were recorded. Each period averaged 36 closings per day or 3.5 per 1,000 crossing vehicles. The largest percentage of closings, 17%, occurred from 6:00 p.m.
through 9:00 p.m. A total of 367 violations were counted during the period when train horns were in use. Only 97 violations were recorded once the wayside horns were in operation. The
average violation rate when train horns were in use was 3.53 per 100 gate closings. This decreased 68% to 1.12 per 100 closings with the A WHS. The decrease is statistically significant.
Type 1 violations (driving under a descending gate) occurred 358 times in the before period and 93 in the after period. A combined total of 13 drivers in both periods went around a gate.
With few exceptions, most of the Type 1 violations occurred within the first two seconds after the gates began their descent. Ofthe Type 1 violations recorded when train horns were in
use, more than 90% occurred between 6:01 a.m. and 9:00 p.m. Between 12:01 and 3:00 p.m., 30% of all violations occurred. The largest percentage occurred on Hawley Street. Part of the
problem stems from multiple gate activations when Metra commuter trains stop at the Mundelein station near Hawley Street. A total of 13 instances were recorded where motorists drove
around the gates. Nine occurred during the time the train hom was in use, and four occurred when the A WHS was operating. The decrease is not statistically significant. Approximately
one-half ofthe violations happened when a train arrived during the 60-second recording interval. In one case, a driver cleared the tracks just 6 seconds before a freight train arrived.
On the average, 17 17 seconds separated the vehicle from the train. At 50 mph, a train would just have passed the whistle post; therefore, the motorist driving around the gates generally
might not yet have heard a train hom iftrain horns were being used. As with Type 1 violations, a large percentage ofType 2 violations occurred in conjunction with Metra commuter operations.
One problem uncovered with the gate operations was gate closure without a train present. Often, this is referred to as a "false activation." These activations comprised approximately
13% of all closings. Metra stops at the Mundelein station and switching operations accounted for a majority ofthese activations. Northwestern University Center for Public Safety Wayside
Horn Evaluation -Final Report 3 
Finally, an unusual situation was videotaped during the spring of2002 in which drivers stopped on the tracks in an apparent response to the wayside hom sounding without prior warning.
This happened on 12 occasions. When the drivers went forward, they generally cleared the tracks after the gates had closed just behind them. In other words, in most cases, the drivers
occupied the tracks for 12 or more seconds. In one case, a driver backed up, just clearing the descending gate. Survey of Residents and Engineers Two sets ofsurveys were distributed
to examine opinions of both the wayside hom and its perceived safety effectiveness. The respective surveys were administered to more than 1,250 Mundelein residents and to railroad engineers
for both the Canadian National Railroad and Metra Commuter Rail. Residential survey. The 229 residents who responded to the residential survey, by a substantial majority, found the wayside
hom much less annoying than the train horns. The exception was persons who lived close to and and in a direct line with the wayside hom. More than 15% of respondents found the wayside
hom annoying, and a slightly greater percentage responded that "occasionally" the horns interfered with their activities. When compared to the train hom, 88% found the wayside horns
either less loud or not even noticeable. A similar percentage also found them less annoying. When asked about safety, approximately 9% suggested that they were less safe. The same percentage
believed that motorists would be more likely to violate crossing laws. On the other hand, the remainder ofthe respondents believed that the crossings were as safe or safer with the wayside
hom than they had been with train horns. Engineer survey. Both Metra and Canadian National engineers also responded to surveys. One Canadian National and one Metra engineer believed
that the crossing was less safe. Neither gave a reason for selecting that answer. However, both also did not like the method of notifying the engineer when the horns were not working.
The remaining engineers believed the crossings to be as safe as or safer than when they used the train hom. Analysis of the Sounds from Train and Wayside Horns The key element ofthe
evaluation addressed the differences between the train hom and the wayside hom as it might affect safety of the highway-rail crossing. For the village residents, it was ofequal importance
to compare how the two horns affected their lives. The fmdings are discussed in greater detail in a separate report produced as part of the project. Northwestern University Center for
Public Safety Wayside Hom Evaluation -Final Report 4 
In terms ofoutcomes, the sound level ofthe wayside born was equal to or exceeded that oftbe train born for a driver approacbing a bigbway-rail crossing. The exception was wben the train
reached the crossing, where the train hom was louder. Tbis finding beld for a motorist approacbing the crossing, wbether at the last point wbere tbe motorist could stop safely or at
the sign warning the motorist ofthe approacbing crossing. The two boms bad similar frequency components and were of equal loudness at different frequenCies. Perbaps the greatest difference
was that the wayside born is produced electronically and the train hom by air passing through tuned horns. As a result, the sound of the wayside hom had a certain artificiality. Tbe
wayside hom bad a significant impact on the quality-of-life in areas near the crossings. At the highest decibel levels, the wayside born covered 85% less land area than tbe train-mounted
borns. Even at lower levels, more than 65% less area was affected. Tbe residential survey clearly bore out the findings from sound measurements. On the other hand, some persons were
affected more than before. Some ofthis occurred because the pattern oftbe sound dispersion changed. Volume levels were elongated along the roadway so that some persons heard a louder
hom than before. More importantly, because the horns were ofconstant volume and lasted longer than the train hom, this increased their apparent loudness. Summary and Otber Issues This
evaluation of the automated wayside hom system (A WHS) compared the new system to the train hom. It examined three elements for differences: I. Motorist violations of the law governing
gated highway-mil crossings along with perceptions of its safety from drivers and railroad train engineers. 2. The nature ofthe sound heard by tbe motorist and tbe potential effects
ofany differences on safety at the highway-rail crossing. 3. Quality-of-life for residents as measured both by sound levels, and how the residents perceived the loudness and annoyance
ofthe two warning devices. With the introduction ofthe AWHS, motorists' violations of the crossing gates decreased 68%. This difference had less than a O.()()OI likelihood ofoccurring
by chance. The largest change came from Type 1 violations or driving under the closing gates. Because so few motorists drove around the gates during the period the train horns were in
use, the decreases occurring during the after period could not be said to be statistically significant. In responses to the surveys, both engineers and residents indicated that they
believed the wayside hom cteated a safer crossing environment for motorists. Because there were no other known cbanges to the operation of the roadways, the wayside hom is the most likely
factor in the reduction of violations. Northwestern University Center for Public Safety Wayside Hom Evaluation -Final Report 5 
The sound studies showed that, in terms of nature and quality of sound, what the motorist heard from the wayside hom was generally no different from what he or she heard from the train
hom. However, there were two differences in sound delivery. The first was that the train hom provides a sense ofmovement because it gradually increases in volume. The wayside hom starts
and remains at a constant volume. The second difference was that the wayside hom sounds when the crossing warning lights first activate while the train horn is usually not heard until
the gates are fully descended. Residential quality-of-life, as measured by the noise levels in the crossing areas, improved significantly with the AWHS. At allievels, from 70 to 90 decibels,
the reductions in area covered by a given decibel level, ranged between 65% and 85%. When residents living near the crossings were surveyed about the wayside horns as compared to the
train horns, more than 80% ofthe respondents indicated that their quality-of-life had improved. Finally, in referring to Type 2 violations (driving around the closed gates), none occurred
at Allanson Road. At this crossing, there is a 6-inch raised concrete median that extends approximately 40 feet back from the tracks. While this does not quite meet the proposed FRA
standards, it appears to have been sufficient in preventing drivers from going around the gates. Except for the two drivers on Maple who drove around the queue waiting for malfunctioning
gates, all ofthe drivers who went around the gates were the first vehicles in line. Restricting the driver's ability to pull out around the gates for between 30 and 40 feet back from
the gate, along with the presence ofthe wayside horn, prohably would eliminate almost all Type 2 violations. The conclusion then drawn from this study is that the wayside hom significantly
reduces highway-rail crossing violations. It accomplishes this task while improving the quality-of-Iife for nearby residents. Northwestern University Centerfor Public Safety Wayside
Horn Evaluation -Final Report 6 
RCLRailroad Con'rols Limited Comprehensive Signal & Communication Services January 24, 2003 Mr, Jim Pierce Asst City Engineer City of Addison 16801 W, Grove Drive PO Box 9010 Addison,
TX 75001 Re: Automated Horn System Press Releases from Mundelein, IL Dear Mr. Pierce: In an effort to keep you updated as to the continued progress of the Automated Horn System (AHS)
in eliminating noise pollution in neighborhoods located near railroad tracks while improving the safety at railroad crossings, Railroad Controls Lintited is pleased to provide you with
copies of press releases from Congressman Mark Kirk, 10"' District, IUinois, Lake County and the Village of Mundelein regarding the results of Noriliwestern University Center of Publie
Safety's evaluation of the AHS. AJso included are the executive summaries from the report "Evaluation of the Automated Wayside Horn System in Mundelein, Illinois". The scope of the study
was to determine the reduction in noise pollution to neighborhoods located adjacent to the railroad traeks and to evaluate the overall safety at the crossings once the AHS was installed.
The report concluded that the AHS reduced noise pollution by 80"/0 and decreased highway violations by 70%, The findings of this report indicate that the AHS improved railroad crossing
safety while decreasing noise pollution created by trains sounding their horns. Congressman Kirk plans to deliver the findings of this report personally to Federal Railroad Administrator
Allan Rutter in Washington DC If you have any more questions or would like to obtain information on the AHS please visit our web site at www.railroadcontrols.eomlahsor contact Kurt Anderson
or myself at (& 17) &20-6347. Best regards, /fJ;) Robert AJbritton National Sales Manager Railroad Controls Limited Ene. 7471 Benbrook Parkway. Benbrook, IT 76126.817-820-6300. Fax 817-820-6340

• MARK STEVEN KIRK lOrn DtSTfUCT, IlUNOIS WASHINGTON Orncf: 1531 lO!'<GWORTH HOUSI!. OFFICE !rullOIflG WAStftHIlTON, OC20515 f20:(j 225--4835 FAX: 1202. 225--0831 CoMM!TIEES: Rep, Kirk@maiLhouse,gov
BUDGET 􀀨􀀺􀁯􀁮􀁧􀁴􀁥􀁾􀁾􀀠of !be mniteb 􀁾􀁴􀁡􀁴􀁾􀀠OEERflWQEf!CJi:;E)ou5t of l\tptt5tntatibt5 102 WILMOT ROAD. SUITE 200TRANSPORTATION AND OeERFIELO, Il 60015lNFRASTRUCTURE (8471 '940-0202
SiIBCQMMlTIEES; .nl!flington. 1BQ[; 20515-1310 FAX: (847)940-7143AWA1l0N HIGHWAYS AND TRANSIT Contact: Dodie McCracken 301􀁾􀁁􀁾􀁾􀁉􀀺􀀧􀁔􀀺􀁦􀁾􀀡􀁥􀁅􀁔􀀠ARMED SERVlCES 847-940-0202
w'f..􀀢􀁩􀁬􀁾􀁩􀀡􀀺􀀺􀀧􀀢􀀧$!BCQMMrmES' MIUTARY PROCUREMeNT cell: 847-921-1191 􀁆􀀢􀀢􀀧􀁾􀀷􀀵􀀱􀀹􀀠􀁍􀁬􀁾􀁉􀁔􀁁􀁦􀁬􀁙􀀠PEflsow.a CONGRESSIONAL HUMAN RlGHTS CAUCUSJanuary 21, 2003 For
Immediate Release Congressman Kirk Says New Federally Funded Study Found Automated Wayside Hom System Increased Safety, Improved Quality ofLife and Costs Less Than Proposed Alternatives
To Meet Train Whistle Mandate Mundelein, IL --As part ofhis continuing efforts to to prevent implementation of a proposed federal regulation that would require trains to blow their horns
at all railroad crossings, U.S. Rep. Mark Kirk (R-Highland Park) joined members ofa multijurisdictional task force to announce the results ofan "Automated Wayside Hom System" study.
The task force, convened by the Village ofMundelein, hired Northwestern University's Center for Public Safety to conduct the automated train horn evaluation. "Safe railroad crossings
are a top priority in our communities," said Congressman Kirk. "I am very encouraged by the results ofthis comprehensive study which revealed that use ofthe Automated Wayside Hom System
resulted in a 70 percent decrease in highway violations at rail crossings and an 80 percent noise level reduction near the tracks. According to this report, wayside horns increased public
safety, reduced the impact oftrain horns on our quality of life and will save money as communities work to comply with the FRA train whistle mandate. 1 applaud the Villages ofMundelein,
Libertyville and Vernon Hills for taking the lead in initiating the task force which lead to this study that 1 intend to hand deliver to Federal Railroad Administrator Allan Rutter in
Washington. " -more
·' Congressman Mark Kirk -page two In August of200 I, Congressman Kirk brought FRA Administrator Rutter to the 10th District to emphasize local opposition to the federal train whistle
mandate and for a first-hand look at communities where implementation ofthe current FRA regulation would mean that a train traveling through some communities where intersections are
very close would be continuously blowing its' horn. "Our suburban mayors and village presidents have joined the effort to prevent this train whistle mandate from destroying our quality
oflife and diminishing O.ur property values," said Congressman Kirk. "The study being released today indicates we do not have to forgo safety to protect our quality oflife and still
comply with federal law. I will ask the FRA to consider the Automated Wayside Horn System as an alternative to train horns proposed to satisfY the federal mandate." The task force, which
began meeting in June 1999, consists ofthe Villages of Mundelein, Libertyville and Vernon Hills, the Federal Railroad Adrrii.nistration, lllinois Commerce Commission, lllinois Department
ofTransportation, Metra, Wisconsin Central, Canadian National Railroad, Lake County Department ofTransportation, Northwestern University, and Railroad Controls, Ltd. After numerous meetings,
the task force succeeded in obtaining state and federal fonding to install nine automated horns on an experimental basis (from Paterson to Butterfield Road), and federal funding to conduct
a study ofthe effectiveness ofthe horns as a safety device and at reducing the noise . disturbances to the community. The Village ofMundelein, and members ofthe task force, asked the
Northwestern University Center for Public Safety to evaluate the effectiveness ofa demonstration installation ofwayside horns. The study was conducted with federal and local matching
funds under auspices of the Federal Railroad Administration and Volpe National Transportation Research Center. Although the horns are installed at all nine crossings in or near the Village,
only three were used in evaluation. The horns were installed at an average cost of$52,000 per location and activated in March 2002. 
.' -more Congressman Mark Kirk -page three To satisfY the safety and quality oflife objectives ofthe study, data was gathered for five measures: motorists violations ofthe crossing gates,
sound levels at various distances along the roadway approaching the crossing, sound levels in occupied areas at various distances from the railroad crossings, train engineers' perceptions
ofsafety, and residents' perceptions ofquality of life as related to the sound levels. The Automated Wayside Hom System is a stationary hom system activated by the niilroad-highway grade
crossing warning system. The automated hom system, which is designed to sound like a train hom, is mounted at the crossing, rather than on the locomotive, to deliver a more consistent
audible warning to motorists and pedestrians while eliminating noise pollution in neighborhoods for more than halfa mile along the rail corridor. For more information on Automated Train
Horns, visit www.railroadcontrols.comlahs. ### 
NEWSVillage of Mundelein 440 East Hawley Street Mundelein, IL 60060 RELEASE FOR DISTRIBUTION JANUARY 21, 2003 Contact: Larry Hasvold, Regional Administrator Federal Railroad Administration
(312) 886·9634 or Beth Bosch Office ofPublic Affairs lllinois Commerce Commission (217) 782-5793 EVALUATION OF THE AUTOMATED WAYSIDE HORN SYSTEM IN MUNDELEIN, ILLINOIS FINAL REPORT On
January 21, 2003 the Northwestern University Center for Public Safety delivered its Final Report on the Evaluation ofthe Automated Wayside Horn System in Mundelein, Illinois to the Village
of Mundelein. The study was commissioned by the Village and the Wayside Hom System Task Force to determine if the Wayside Homs that were installed at 9 crossings in, and aCijacent to,
the Village were effective safety devices and significantly reduced noise levels from train horns within the community. -The Final Report will now be sent to the Dlinois Commerce Commission
(ICC) and the Federal Railroad Administration (FRA) for critical review and analysis. In the months ahead both the lllinois Commerce Commission and the Federal Railroad Administration
will independently evaluate the findings of this study. The lllinois Commerce Commission has permitted the current installations in Mundelein on an experimental basis. The ICC Order
authorizing the Mundelein installations expires April 25, 2003. If the Wayside Horns are to remain in Mundelein beyond this date, the ICC will have to extend the current Order following
a hearing before the Commerce Commission. The Federal Railroad Administration is in the process of reviewing an Administrative Rule that could require trains to sound an audible warning
at all crossings unless approved safety devices are in place. At the present time Wayside Horns are not included on the FRA's list of such approved safety devices. 
-------------Comparison of Train and Wayside Horns in Mundelein, Illinois: Analysis of Sounds at Highway-Rail Crossings and in Residential N eighhorhoods_____ _ Northwestern University
Center for Public Safety 405 Church Street Evanston, IL January 2003 
Comparison of Train and Wayside Horns in Mundelein, Illinois: Analysis of Sounds at Highway-Rail Crossings and in Residential Neighborhoods Executive Summary Introduction Railroad train
horns appear to improve safety at highway-rail grade crossings, even ones with crossing gates. However, the loudness of these .horns can be a significant nuisance for residents living
near the crossings. For this reason, the Village ofMundelein, Illinois, tested the use of an 􀁟􀁾.. _ _ 􀁁􀁵􀁴􀁃􀁬􀀮􀀮􀀮􀁭􀁡􀁴􀁾􀀨􀁴􀁗􀁾􀀩􀀧􀀿􀁬􀁩􀀨􀀺􀁬􀁥􀁊􀀡􀁑􀁭􀀠System (A WHS), which
is mounted at the crossings and directs the hom sound down the roadway. The purpose is to alert the motorist ofan approaching train 􀁾􀁨􀁩􀁬􀁥􀀠... reducing the noise directed toward
residential areas. JSirrent FederiilRailroad Administration (FRA) rules require that railroad train horns be capable ofgenerating 96 decibels (dB) at 100 feet (30.5 meters) in the forward
direction ofthe train. While the horns are. aligned with the direction of train travel, directivity plots ofsound levels show that these sounds radiate with minimal decrease up to 60
degrees to each side. This would mean that persons residing away from the railroad would be subject to approximately the same sound volume as those near the tracks. The analysis of sound
levels and acoustical characteristics heard by motorists show minimal differences between the railroad hom and the wayside hom. Motorists approaching the crossing when the gates are
being lowered are more likely to hear the wayside hom because it is much louder than the approaching train's horn. Once the motorist is at the gate, the train horn becomes ······----·lUuUer·thanthcwa
yside horn only when the train is within a few seconds of reaching the 􀁣􀁲􀁯􀁳􀁳􀁩􀁮􀁾.. -'Frequency aii,rtemponiIcluiractenstics ofboth horns are similar, with patterns over the normal
ranges for hearing. Finally, residential areas experienced a significant reduction in sound levels once the wayside horns were introduced. In many cases, the wayside horn could not not
be distinguished from background noises. Hrief Introdllction to Measuring Sound Sound and noise often are used interchangeably to describe a sensation that can be detected by the ear.
However, the study ofsound (acoustics) often distinguishes between noise as "unwanted sound" and sound as an "auditory sensation produced through the ear by alteration in pressure ...
" Northwestern University Center for Public Safety Mundelein Sound Final Report 1 
Sound travels through most media, e.g. air, water, and metal, as a wave that has both amplitude defining loudness, and a cycle length that defines frequency. Amplitude is the "strength"
ofa sound wave, and it represents loudness. It is measured as sound pressure. The common measure is decibels and it is knoym as the sound pressure level (SPL). When comparing similar
sounds, a useful set ofrelationships can be employed in describing the change in loudness ofa sound. These are; a 3 dB increase represents a just noticeable difference, a 5 dB change
is considered a significant increase, and a 10 dB change represents a doubling of loudness: Sound also is described by the number ofoscillations or cycles per second (notated as Hertz
Hz); this is the frequency. Although the frequency range ofhearing is considered to be 2020,000 Hz, the·earis-oot-eqwillrsensitiye-to-allthese frequencies. Frequencies from 1,000 to
4,000 Hz are heare} best_ 􀁟􀁟􀁾􀀮􀁟􀀠T4e length oftime_the.sollnd is beard makes a difference in how the listener perceives the sound. A very loud sound with a yery short duration,
e.g., a gunshot, may not be as noticeable as a sound with a lower decibel reading but heard over a longer period. For this study sound was measured using digital audio tape and an "integrating
sound level meter." 1bis device captures the sound in a manner similar to how the human hears. It calculates the sound pressure levels over various periods, usually one second, weights
the . reading, and stores the weighted result fur each period. . While the integrating sound level meter can produce many metrics, two are commonly displayed: the "equivalent continuous
sound level" denoted by L"q and the maximum sound level, LMax. The Leq is the c()l!8.tant leveLof sO..1!!ld, in dB,Jhllt contains the same energy as the actual fluctuating noise over
a stated time interval. The maximum SPL (denoted by Lm.x) is a metric used to capture the greatest.noiseleveLobserved over the sampling period. Various levels are .. used to describe
the sound heard heard over. a.given.period, but the two most common are 40 -the level exceeded 90% oftfiitiine(often referred to a the background or ambient level) and Li0the level exceeded
10% ofthe time. (or intrusive noise levels). Finally, the exposure level (SEL) is an energy average ofnoise over a certain time interval (like the Leq), but it is normalized to one second.
For example, a one-hour Leq is found by averaging the one-second Leq's for the period, where as the SEL for that period is a summing ofthe same one-second Leq's. Because of its norma1ization
the SEL is useful for comparing the effect of •events with different maximum levels and durations.. Northwestern University Center for Public Safety MWldelein Sound Final Report 2 
Acoustical Comparison of Train vs. Wayside Horns 'This is a comparison ofthe acoustical parameters ofsound generated by conventional trainmounted horns with the wayside pole-mounted
horns. To assess the sound levels generated by train-mounted horns vs. wayside horns, sound level data were collected by digital recordings. Two locations within the Village ofMundelein,
liIinois, were selected for the recording sites. The Hawley Street crossing was selected because ofits location downtown near reflective buildings and residential properties. The second
site at the Winchester Road crossing was selected because ofits· location away from reflective buildings and is also more distant from residential properties. Two monitoring stations
were used; 'one at I 10 feet from the centerline of the crossing and the second location at 300 feet. These represented two different points at which motorists would be . expected to
respond to train or wayside horns.-Data-sampling-for-thelocomotive horns were made on in December 200 200 I. The sapling for th\' 􀀢􀁉􀁙􀀡􀁬􀀧􀁹􀁾􀁩􀁤􀁥􀀠horns occurred late May/early
June 2002. Train-mounted horns are typically multi-tone, air-driven devices intended to emit a high sound intensity level. Each hom produces a different fundamental frequency (pitch).
Usnally, these sounds are dissonant meaning that the fundamental frequencies are not musically aligned. 'This dissonance adds to its alerting function. The wayside hom sound was created
from a digital recording ofa typical train hom. As such, few differences between the bannonic structures of the two types ofhorns were expected. However, there are other acoustical characteristics
ofa train hom that make it different from a wayside hom. This includes a ramp effect -the increase in amplitude as the train 􀁡􀁰􀁰􀁲􀁯􀁡􀁣􀁨􀁥􀁳􀀬􀁴􀁨􀁾􀀮􀁄􀁯􀁰􀁰􀁬􀁥􀁲􀀠Effect -a slight
upward shift in frequency as the train approaches the crossing, and interference effects -the fluctuation in amplitude as the sound arrives at the listener by various direct and reflective
paths that provide constructive and destructive interference. ". It was not the purpose of this study to perform.an.exhaustive.analysis oftrain and wayside horns. However, it was importantto
verifY that the spectraI energy. inbo.th cases is similar. These data confirm that, although the angle ofincidenCe is afactor, because the amplitude and frequency content of the two
types ofhorns are similar, the audibility inside a vehicle should also be similar. In other words, the sound transmission loss provided by a vehicle to diminish the intensity ofthe wayside.hom
would have the same effect on a train hom signal as well. Train horns typically produce 􀁁􀁾􀁷􀁥􀁩􀁧􀁨􀁴􀁥􀁤sound levels ofabout 105 dB(A) at 100 feet. The typical hom is a blast of"longclong-short-I
ong." For the second and third long blasts (when the train is Close to or at the crossing) the ayerage 8Pt was 92 arid 103 dB(A), respectively. The 2nd blast is lower simply because
of a greater distance to the recording station. The blasts from the wayside hom were uniform. Each ranged from approximately 94 to 97 decibels. The single greatest difference was that
the loudness ofthe train hom increased as the train approached. The wayside hom was constant. Northwestern University Center for Public Safety Mundelein Sound Final Report 3 
The sound levels at 300 feet from the crossing approximated those at 110 feet Both horns were slightly lower in volume because ofthe added distaoce from the source. Variability ofthe
train horns was greater at this distaoce because ofthe opportunity for more factors to influence the sound levels. One major difference between the two horns was duration. While the
sequences from the train and wayside hom were each approximately 17 seconds, the wayside hom sounded over two or more complete sequences, some as long as 45 seconds. These findings are
importaot ifthe purpose ofthe wayside horn is to match the purpose ofthe train hom. In other words, it may be insufficient to simply reproduce the static amplitude, frequency, and duration
ofa train horn blast. Ofimportaoce may also be mimicking .the dynamic features ofa train hom, which would be to include only one sequence, adjusting the onset ofthe sequence, and providing
an amplitude . ramp to avoid startling pedestrians. C9mparison ofSound Levels in Residential Areas To obtain a better understanding ofchanges in the sound levels in areas near crossings
from when the train hom was being used to after the wayside hom began operating, the Northwestern University Center for Public Safety (NUCPS) conducted sound studies in residential yards
..The research team used an integrating sound level meter for the recordings. These were taken in 􀁯􀁮􀁥􀁾􀀠secondintervals over a period of24 hours for each location. Residents were located between 500 and 1,500 feet from that portion ofthe tracks where use ofa train hom was expected. Sound samples
were taken at a set ofresidences over a two-week period, in the fall of2001 and again in the spring of2002. With availability ofvideotapes for drivers at crossings near the sampling
sites, the arrival ofa train could be linked to the actual recordings. For the train horns, their hom patterns were loud enough to present distinct differences in the loudness ofthe
recorded data. This was not the case for wayside horns where many times, their their volume was only slightly louder than the background nOIse.. Although the readings were taken a varying
distances from the tracks and subject to varying levels ofinfluence on their loudness (buildings, vegetation, etc.), when the Leq was converted back to an expected level at 100 feet
from the front ofthe train horn, the resulting adjusted dB readings were very similar. They differed by 6 dB from 99 dB to 105 dB. For the wayside hom, conversion back to the hom was
within 3 dB of that level recorded at the selected distance of 110 feet. A four-hour nighttime block from 8:00 p.m. to midnight was chosen for making comparisons because that is when
the horns are most likely to be heard by the residents. The maximum decibel reading with train horns during the four nighttime hours for any location was 84 dB at Northwestern University
Center for Public Safety Mundelein Sound Final Report 4 
two locations; the highest SEL was 95 dB. Backgro\ll1d levels 􀀨􀁾􀀩ranged from 42 dB to 52 dB. The average sO\ll1d levels of train horns during the four hours ranged between 10 dB and
30 dB above the 10% level, and generally were 30 dB higher than the backgro\ll1d level. The maximum: reading of75 dB for the wayside hom occurred at the Village Hall. It also was the
closest location to the wayside hom, as well as directly in line with the direction of the speaker. The lowest maximum reading was 61 dB. On several occasions at a number of locations,
the wayside horn could not be distinguished from the backgro\ll1d level even when the train was known to be present in part because ofthe lower level ofsO\ll1d detected at a location
and an increase in backgro\ll1d noise levels during the spring. With the exception ofthe Village Hall, all median SEL's decreased. At three locations, the decrease was 3 dB or less;
the largest decrease was 27 dB. . 􀀭􀀭􀀢􀀮􀁾􀀢􀀭􀀭􀀮􀁅􀁱􀁵􀁡􀁬􀀠contours ofloudness were mapped using five contours representing 70,75, SO, S5, and 90 dB. For example, the 70 dB contour
produced by the train horns covered 4.29 square miles (mil) rel'resenting 37% ofthe 7.79 mil computed for the entire village. The 90 dB coverage was 0.36 .milor approximately 230 acres.
'This represented 3.8% ofthe village area. Because the sO\ll1d from the train horn radiates fairly constantly over a ISO-degree sector, the sO\ll1d pattern for both directions oftravel
approximates a slightly flattened circle decreasing by one-half for each 5 dB decrease. Based on the attenuation ofsO\ll1d, a decrease in area by one-half for each:> dB increase would
have been expected. On the other hand, the wayside hom is very directional with most ofthe sO\ll1d energy occurring along the primary speaker axis. Outside that axis, the drop-off in
SO\ll1d is rapid. This is evident in the plot of contours based on sO\ll1d readings from the wayside horns. The 90 dB reading for the wayside hom cover 0.02 mil, approximately 14 acres
or 93% less area than the train hom. The decrease in area covered at 70 dB was somewhat less. Concluding Comments Use ofthe wayside hom, from an analysis ofso\ll1d, is no different from
the train hom. It is of equal loudness and covers the same :frequency spectra. Given its directiouality, the wayside horn may be more likely to be heard by the motorist and less likely
by the residents. For those people living in Mundelein, the wayside hom has generated a significant improvement in quality of life in terms ofa substantial reduction of noise pollution.
Train Homs,'Wayside Horns, and Motorists. The sO\ll1d levels at various frequencies from the wayside horn Closely match the train horn. While the wayside hom sounds similar to the train
horn, the operation ofeach is different. With few exceptions, motorists approaching a gated highway-rail crossing always are alerted to the presence of a train prior to when the train
horn sO\ll1ds. The bells, flashing lights, and descending gates serve this function. The train horn normally is not heard until 3 to 5 seconds after the gates fully descend. On the other
hand, the Northwestern University Center for Public Safety Mundelein Sound Final Report 5 
motorist approaching a crossing with a wayside hom immediately hears the hom when the signals activate. One problem is that because the wayside horns sounds at the same time the signals
start to operate, the motorist has no warning for the loud noise. As a re:ruJ.t, the wayside hom has startled and confused people. On at least 12 occasions, motorists stopped on the
tracks and proceeded only after the gates had begun to descend. Residential Sound. Implementation ofwayside horns has made a significant difference in the residential quality of life
from when the train-mounted horns were used. Some residents who· were located several hundred feet from the tracks were hearing sounds above 90 decibels (similar to a jackhammer at 5
feet) at all times ofday and night. Because ofthe relatively low background noise level, the train horns were ofthe magnitude of 8 to 16 times louder than the ....... --backgroumL.Moreoller•.the.loud
sounds were not limited to a relatively small area. The 85 dB 􀁃􀁾􀁾􀁌􀀡􀁏􀀡example, covered approximately 0.71 square miles ofthe village. ___Once the wayside hof.!1! were installed,
sound coverage, especially at higher volumes, decreaSed .by.a.factoLof 10. Those benefiting the most lived at angles of45° or more from the wayside hom. The problem that has arisen,
ofcourse, is that not everyone benefited. In a few cases, the volume recorded actually has increased. More importantly for a larger number ofpersons the sound exposure level also has
remained approximately constant, or, perhaps, even increased. If the wayside hom more closely rllirnicked the train hom, this would reduce the length ofits use as well as gradually increasing
in volume. Northwestern University Center for Public Safety Mundelein Sound Final Report 6 
.' Evaluation of the' Automated Wayside Horn System in Mundelein, Illinois Final Report Northwestern University Center for Public Safety 405 Church Street Evanston,IL January 2003 
Evaluation ofthe Automated Wayside Horn System in Mundelein, Illinois Final Report Executive Summary Highway-Rail Crossing Safety and Train Horns At highway-rail grade crossings, the
train hom serves to warn motorists ofa train's immediate approach. The hom advises motorists, and other crossing users such as bicyclists and pedestrians, that entering on or crossing
the tracks would place them in imminent danger. However,. because ofthe loudness and the wide angle ofsound radiation, the hom can be an intmsive nuisance, especially in residential
areas near the tracks. As a result, an automated wayside hom system (AWHS) has been developed to provide an appropriate warning for those using the crossing, while not annoying those
living near the tracks. A study was carried out in Mundelein, Illinois, that compared the train hom with the A WHS. This report compares motorists' driving behavior at highway-rail crossings
and the sound levels ofthe two types ofhorns. The results from the evaluation show a significant 70% decrease in violations ofhighway-rail crossing law with the A WHS. Noise levels in
areas near the tracks decreased by up to 85%. Reducing the number ofcollisions between vehicles and trains has remained a priority in highway safety. During the past 10 years, collisions
nationally have decreased from 4,684 in 1992 to 3,064 in 2001 (Federal Railroad Administration). During this same period, all collisions with trains in Illinois remained fairly constant
with an average of232 per year. Even though there has been a general decrease nationally, these collisions remain the most severe type in terms ofproducing injuries and fatalities. Crossing
gates have the best record at reducing collisions, but a study done in Florida showed that even with crossing gates, a train hom still is needed. The Federal Railroad Administration
(FRA) has proposed rules to require that norns be used at all crossings with few exceptions that are expensive to implement. The problem remains that the train horn, which, in Mundelein,
stsrts stsrts soUnding approximately 17 seconds before the train reaches the crossing, creates very high sound levels in adjoining areas. As a result of the need to alert motorists and
at the same time reduce the effect ofsound on adjoining areas, Mundelein experimented with the use ofthe A WHS. The study reports the results ofthe evaluation ofthe A WHS. Northwestern
University Center Jar Public Safety Wayside Horn Evaluation -Final Report 1 
'. Conduct ofthe Study Five tasks were undertaken: site preparation, before and after motorist violation studies, before and after sound studies, quality-of-life studies, and surveys
ofengineers and residents. At each ofthe three sites used for studying motorist behavior, utility poles were erected, and cameras and recording equipment installed. The recorders activated
when the warning signals activated, thereby recording what motorists did during the period the gates were descending and down before the train arrived. Drivers are considered to be taking
risks (and violating the law) when they attempt to cross the tracks after the crossing gates start to descend. This action was measured by viewing videotapes made at each crossing during
the period the gates were activated. Data were taken during the period train horns were in use, then after a peri<.>d ofadaptatioo.-when-the-wayside..bom was in use. The violations were
divided into tWo classes: Technical violation where the driver crosses the ..􀁾􀁴􀁴􀀺􀁬􀁩􀀮􀁳􀁴􀁡􀁲􀁴􀀮to descend but before the gate has beeillowered sufficiently to block the vehicle's
passage, labeled a "Type 1 n violation, and . Deliberate violation in which the driver either drives through or around the lowered gate. These are "Type 2" violations. Loudness and sound
characteristics were measured on approaches to several crossings with train homs in use and then after the wayside horns were a!)tjyated. A comprehensive assessment of these measures
is contained in a separate report; this final report just summarizes the findings. Measures of quality oflife derived from tWo sources: sound studies in residential yards and a survey
ofthe residents. The project team measured sound levels over 􀀲􀀴􀀭􀁨􀁯􀁵􀁲􀁾􀁰􀁥􀁮􀁯􀀨􀁦􀁳􀀭at nine locations throughout Mundelein. These measures were made..dnring the. period when
train horns were used and again after the wayside horns.wereplaced in service. Comparisons included the average sound level in one-second periods, during the tinie fuatIioms were sounded,
and a sound exposure level. The latter takes into account duration and allows direct comparison ofsounds between different locations and over different periods. In addition, surveys
were sent to a sample ofresidents in Mundelein. The survey asked residents how they viewed the new horn systam compared to the train horns, Several questions also were directed toward
the residents' views ofchanges in 􀁾􀁯􀁳􀁳􀁩􀁮􀁧􀀠safety. Finally, a survey was distributed to engineers from both the freight railroad (Canadian National) and commuter rail (Metra).
This survey was modeled after the one used in Ames, Iowa, for a Northwestern University Center for Public Safety Wayside Horn Evaluation -Final Report 2 
.' similar evaluation. It asked the engineers how they perceived the crossing safety before and after the wayside horns were activated. Evaluation of Cbanges in Crossing Violations From
the period September 8 through December 20, 2001,10,392 gate activations were recorded on videotape at three crossings. During the second period ofobservations, April 12 through July
16, 2002, 9,112 activations were recorded. Each period averaged 36 closings per day or 3.5 per 1,000 crossing vehicles. The largest percentage ofclosings, 17%, occurred from 6:00 p.m.
through 9:00 p.m. A total of 367 violations were counted during the period when train horns were in use. Only 97 violations were recorded once the wayside horns were in operation. The
average violation rate when train horns were in use was 3.53 per 100 gate closings. TIris decreased 68% to 1.12 per 100 closings with the A WHS. The decrease is statistically significant.
Type 1 violationS .(driving under a descending gate) occurred 358 times in the before period and 93 in the after period. A combined total of 13 drivers in both periods went around a
gate. With few exceptions, most ofthe Type 1 violations occurred within the first two seconds after the gates began their descent. Ofthe Type 1 violations recorded when train horns were
in use, more than 90% occurred between 6:01 a.m. and 9:00 p.m. Between 12:01 and 3:00 p.m., 30% ofall violations occurred. The largest percentage occurred on Hawley Street. Part ofthe
problem stems from mUltiple gate activations when Metra commuter trains stop at the Mundelein station near Hawley St. A total ofthirteen instances were recorded where motorists drove
around the gates. Nine occurred during the time the train hom was in use, and four occurred when the A WHS was operating. The decrease is not statistically significant. Approximately
one-half the violations happened when a train arrived during the 60-second recording interval. In one case, a driver cleared the tracks just 6 seconds befQre a freight train arrived.
On the average, 17 seconds separated the vehicle from the train. At 50 mph, a train would just have passed the whistle post; therefore, the motorist driving around the gates generally
might not yet have heard a train hom if train horns were being used. As with Type 1 violations, a large percentage ofType 2 violations occurred in conjunction with Metra commuter operations.
One problem uncovered with the gate operations was gate closure without a train present. Often, this is referred to as a "falseactivation." These activations comprised approximately
13% ofall closings. Metra stops at the Mundelein station and switching operations accounted for a majority ofthese activations. Northwestern University Center for Public Safety Wayside
Horn Evaluation -Final Report 3 
Finally, an unusual situation was videotaped during the spring of2002 in which drivers stopped on the tracks in an apparent response to the wayside hom sounding without prior warning.
This happened on 12 occasions. When the drivers went forward, they generally cleared the tracks after the gates had closed just behind them. In other words, in most cases, the drivers
occupied the tracks for 12 or more seconds. In one case, a driver backed up, just clearing the descending gate; Survey of Residents and Engineers Two sets of surveys were distributed
to examine opinions ofboth the wayside hom and its perceived safety effectiveness. The respective surveys were administered to more than 1,250 Mundelein residents and to railroad engineers
for both the Canadian National Railroad and Metra Conunuter RaiL Residential survey. The 229 residents who responded to the residential survey, by a substantial 􀁭􀁾􀁪􀁯􀁲􀁩􀁴􀁹􀀬􀀠found
the wayside hom much less annoying than the train horns. The exception was persons who lived close to and in a direct line with the wayside hom. More than 15% of respondents found the
wayside hom annoying, and a slightly greater percentage responded that "occasionally" the horns interfered with their activities. When compared to the train hom, 88% found the wayside
horns either less loud or not even noticeable. A similar percentage also found them less annoying. When asked about safety, approximately 9"10 suggested that they were less safe. The
same percentage believed that motorists would be more likely to violate crossing laws. On the other hand, the remainder ofthe respondents believed that the crossings were as safe or
safer with the wayside hom than they had been with train horns. Engineer survey. Both Metra and Canadian National engineers also responded to surveys. One Canadian National and one Metra
engineer believed that the crossing was less safe. Neither gave . a reason for selecting that answer. However, both also did not like the method of notifying the _ engineer when the
horns were not working. The remaining engineers believed the crossings to be as safe as or safer than when they used the train hom. Analysis of the Sounds from Train and Wayside Horns
The key element ofthe evaluation addressed the difrerences between the train hom and the wayside horn as it might affect safety ofthe highway-rail crossing. For the village residents,
it was ofequal in'iportauce to compare how the two horns affected their lives. The findings are discussed in greater detail in a separate report produced as part ofthe project. Northwestern
University Center for Public Safety Wayside Horn Evaluation -Final Report. 4 
In terms ofoutcomes, the sound level ofthe wayside hom was equal to or exceeded that ofthe train hom for a driver approaching a highway-rail crossing. The exception was when the train
reached the crossing, where the train hom was louder. This finding held for a motorist approaching the crossing, whether at the last point where the motorist could stop safely or at
the sign warning the motorist ofthe approaching crossing. The two horns had similar frequency· components and were ofequal loudness at different frequencies. Perhaps the .greatest difference
was that the wayside hom is produced electronically and the train hom by airpassing through tuned horns. As a result, the sound ofthe wayside hom had a certain artificiality. The wayside
hom had a significant impact on the quality oflife in areas near the crossings. At the highest decibel levels, the wayside hom covered 85% less land area than the train-mounted horns.
Even at lower levels, more than 65% less area was affected. The residential survey clearly bore out the findings from sound measurements. On the other hand, some persons were affected
more than before. Some ofthis occurred because the pattern ofthe sound dispersi=-____..____ changed. Volume levels were elongated along the roadway so that some persons heard a louder
hom than before. More importantly, because the horns were ofconstant volume and lasted' . .longer than the train hom, this increased their apparently noise. Summary and Other Issues
This evaluation ofthe automated wayside hom system (AWHS) compared the new system to the train hom. It examined three elements for differences: 1. Motorist violations ofthe law governing
gated highway-rail crossings along with perceptions of its safety from drivers and railroad train engineers. ....-. 2. The nature of the sound heard by the motorist and the potential
effects of any differences on safety at the highway-rail crossing. . ....__..__....__. 3. Quality oflife. for residents as measured both by sound levels, and how the residents percei
ved the loudness and annoyance ofthe two waming devices. With the introduction ofthe A WHS, motorists' violations ofthe crossing gates decreased 68%. This difference had less than a
0.000 I likelihood ofoccurring by chance. The largest change came from Type I violations or driving under the closing gates. Because so few motorists drove around the gates during the
period the train horns were in use, the decreases occurring during the after period could not be said to be statistically significant. In responses to the surveys, both engineers and
residents indicated that they believed the wayside hom created a safer crossing environment for motorists. Because there were no other known changes to the operation ofthe roadways,
the wayside hom is the most likely factor in the reduction ofviolations Northwestern Untversity Center for Public Safety Wayside Horn Evaluation -Final Report 5 
The sound studies showed that, in tenns ofnature and quality ofsound, what the motorist heard from the wayside hom was generally no different from what he or she heard from the train
horn. However, there were two differences in sound delivery. The first was that the train hom provides a sense ofmovement because it gradnaUy increases in volume. The wayside hom starts
and remains at a constant volmne, The second difference was that the wayside horn sounds when the crossing warning lights first activate while the train hom is usually not heard until
the gates are fully descended. Residential quality oflife, as measured by the noise levels in the crossing areas, improved significantly with the A WHS. At all levels, from 70 to 90
decibels, the reductions in area covered by a given decibel level, ranged between 65% and 85%. When residents living near the crossings were surveyed about the wayside horns as compared
to the train horns, more than 80% ofthe respondents indicated that their quality oflife had improved. improved. Finally, in referring to Type 2 violations (driving around the closed
gates), none occurred at Allanson Road. At this crossing, there 1S-a'6-mch-raised concrete median that exten_ds approximately 40 feet back frolI\t!1e tracks. While this does not_quite
meet the proposed FRA standards, it appears to have been sufficientinpreventing drivers from going around the gates. Except for the tWo drivers on Maple who drove around the queue waiting
for malfunctioning gates, all ofthe drivers who went around the gates were the first vehiCles in line. Restricting the drivers ability to pull out around the gates for between 30 and
40 feet back from the gate, along with the presence ofthe wayside hom, probably would eliminate almost all Type 2 violations. The conclusion then drawn from this study is that the wayside
horn significantly reduces highway-rail crossing violations. It accomplishes this task while improving the quality oflife for nearby residents.-----Northwestern University Center for
Public Safety Wayside Horn Evaluation -Final Report 6 
􀁾􀁉􀁌La keCounty 􀁾􀁾􀀠For Immediate Release Tuesday, January 21, 2003 Contact: Joe Chekouras, Communications Specialist (847) 377-2155 jchekouras@co.lake.il.us Residents' Quality of
Life Improved Thanks to Federal, State and Local Cooperation MUNDELEIN. IL -Thanks to intergovernmental cooperation between federal. state and local government officials and partnerships
with private corporations, the Mundelein area received a reprieve fromthe disturbing noise of train horns that can be heard up totwo miles from railroad tracks. With six railroad crossings
in Mundelein, two in neighboring Libertyville and one in Vernon Hills, and proposed Federal regulations requiring trains to signal at the crossings, residents frequently found their
quality of life affected by the unwanted noise. In an effort to minimize the disturhance for residents and downtown businesses, the Village of Mundelein partnered with the Federal Railroad
Administration, lllinois Commerce Commission, lllinois Department of Transportation, Lake County Division of Transportation, Metra, Railroad Controls Ltd., Villages of libertyville and
Vernon Hills and Canadian National. This task force worked towards the implementation of an Automated Hom System at each of the village's six railroad crossings. The system was activated
on April 12, 2002, and the Northwestern University Center for Public Safety began studying the safety and quality of life benefits of the horn system. -MORE
Quality of Life Improvt:u Thanks to Intergovernmental ......()operation -2 of 3 The Automated Hom System refers to a stationary warning device mounted on a pole to sound an audible warning
at the time an approaching train triggers activation of the railroadhighway crossing device. Results of the Northwestern University study, as announced at a news conference on Tuesday,
January 21s" demonstrate the quality of life benefits the hom system brings to Mundelein. A survey of residents, conducted as part of the study, shows that more than 80% of residents
feel their quality of life has improved as a result of the new hom system. Comments on the survey and letters to Mundelein officials express residents' gratitude and support for the
automated hom system. One resident wrote to officials, " ...for the past ten years the n9ise has been unbearable. I am no longer awakened by the deafening sound of the trains ..... The
Northwestern University study, which used video and sound recording devices to measure noise .levels, show that noise levels decreased by up to 80% near the tracks and the area recording
noise levels of approximately 90 decibels decreased by 87% from approximately 120 acres to 13 acres. According to the conclusion from the Northwestern study, " ...the wayside hom significantly
reduces highway-rail crossing violations. It accomplishes this task while improving the quality of life for nearby 􀁲􀁥􀁳􀁩􀁤􀁥􀁮􀁴􀁳􀀺􀁾􀀠Funding for the study came from a $150,000
grant obtained by the Village of Mundelein through the Federal Unified Worlc Program. A 20% funding match was shared by Lake County, Metra, Railroad Controls, Ltd., Villages of Libertyville,
Mundelein and Vernon Hills and Canadian National. -MORE
Quality of Life Improved Thanks to Intergovernmental Cooperation -3 of 3 ''This project would not have enjoyed such success without the partnerships, both monetarily and through time
and labor, that our task force members put into it," said Village of Mundelein Administrator Ken Marabella, who chaired the task force. "We in Mundelein are thankful that so many levels
of govemment and private businesses were able to come together to make this project work. It's a tremendous benefit to the people of Mundelein." Federal, state, county and village officials
worked with the railroad companies and other private corporations for both the installation and study of the Automated Hom System. -###
􀁾􀁾LakeCounty 􀁾􀁾􀀠For Inunediate Release Tuesday, January 21,2003 Contact: Joe Chekouras, Communications Specialist (847) 377-2155 jchekouras@co.lake.il.us Automated Horn System Improves
Safety at Railroad Crossings MUNDELEIN, IL -A study by the Northwestern University Center for Public Safety demonstrates the safety benefits of the automated wayside horn system being
utilized at six . railroad crnssings that traverse the Village of Mundelein and at two crossings in neighboring Libertyville and one in Vernon Hills. As a pilot program, the study has
national implications on proposed future Federal law and has attracted interest from corrununities across the country. Per proposed Federal Railroad Administration (FRA) law, trains
would be required to audibly signal at all railroad crossings, resulting in a significant noise disturbance and a diminished quality of life for residencies and businesses. The Village
of Mundelein, in an effort to reduce noise from passing trains, installed automated horns at its railroad crossings. Standard crossing gates represent an effective means of preventing
crashes at railroad crossings, resulting in a 60% decrease in vehicle-train collisions over the past two deca(\es. Accidents continue to occur, however, because drivers ignore warnings,
underestimate the speed of approaching trains and drive ·arnund closed gates. -MORE
Automated Horn System Improves Safety -2 of 3 In two separate studies, the Federal Railroad Administration found that when trains sounded their horns at crossings, cmshes decreased compared
to when there is no audible waming. The Swift Rail Act of 1994 requires trains to sound their horns at crossings unless communities utilize four-quadmnt gates, median barriers extending
from tracks or camera systems to picture and ticket violators. The FRA's administrative rules are still pending. Because these physical barriers and camera systems can cost up to $200,000
per crossing, trains horus continue to sound in most communities, causing a deterioration in quality of life for residents and businesses residing up to two miles from crossings. As
an alternative, wayside horns cost approximately $50,000 per crossing and significantly decrease noise disturbances. According to the Northwestern study. crossing violations decreased
by 70% after the . automated hom signals went into place. The study recorded 367 violations when train horns were in use andonly 97 once wayside horns went into opemtion. The study utilized mounted camems to record train, vehicle and pedestrian traffic at Maple Avenue (Illinois Route 176), Hawley Street and
Allanson Road During the before period of the study, taped from September 8 -December 20, 2001, researchers taped 10,392 gate activations at the three crossings. After the wayside horns
went into operation, researchers taped . 9,112 gate activations from April 12:';'July 16,2002. A task force of national, state and local government agencies and private corporations
studied and partially funded the automated hom system installation and Northwestern University study. -MORE
Automated Hom System Improves Safety -3 of 3 The Federal Railroad Administration, Illinois Commerce Commission, nlinois Department of Transportation, Lake County Division of Transportation,
Metra, Railroad Controls Ltd., Volpe National Transportation System Center, Villages of Libertyville, Mundelein and Vernon Hills and Canadian National comprised the task force. According
to Mundelein Village Administrator Ken Marabella, who chaired of the task force, ''This project clearly shows that cooperative partnerships at all levels of government and the private
sector can effectively come together and successfully address important safety and quality of life issues." -m
AHSTMBeL Automated Horn System R:lilro:ul (:onlmls 􀁲􀁪􀁭􀁩􀁬􀁾􀁬􀁬􀀠Improve the Quality of Life In Your Community What is AHSTM ? AHS"". the Automated Hom System, is an innovative railroad
signaling device that significantly improves safety for motorists and pedestrians at railroad-highway grade crossings while dramatically reducing the amount of noise pollution created
by train horns along rail corridors in populated areas, Reduces Noise by 98% Sound Level Trnin Hom AIlS Hom Percent 98% (dBA) Area{ae..,) Areat"..,) Redl!ction >70 165 31 17I 5 31 <I
The Technology AHS", is a stationary hom system activated by tbc railroad-highway grade crossing warning system, AHSlM is mounted at the crossing, rather than on the locomotive, to deliver
a longer, louder, more consistent audible warning to motorists and pedestrians while eliminating noise pollution in neighborhoods for more than one-half (112) mile along the rail corridor.
AHSrn is designcd to sound like a train hom, The tone modules in the AHSTM horns were digitally recorded from an actual locomotive hom, Upon receipt of the signal from the railroad's
track circuit warning system AHSTM mimics the train hom warning by cycling through tbe standard railroad whistle pattern until the train reaches the crossing. Once the train has entered
the crossing AHSru stops sounding its hom, A confirmation signal notifies lhe locomotive engineer that AHS"" is functioning properly, When the locomotive engineer sees tbat tbe confirmation
signal is flashing, he will not be required to sound his hom unless he detects an unsafe condition at the grade crossing. Coordination with the railroad operating company is essential
since AHS'lM is directly connected to the railroad's crossing signal-warning system, Additionally, the railroad operating company must issue instructions to their train crews regarding
the sounding or non-sounding of the train's hom, Railroad Controls Limited 500 South Freeway Phone: (817) 820-6300 Fort Wortb, TX 76104 Fax: (817) 820-6340 
Signal HOUSn __ Sound Comparison Train Horn Train Horn vs. AHSTM􀁴􀁯􀀼􀁗􀁩􀁯􀁖􀁉􀁾􀀢􀀠The two noise footprints to the left depict the area impacted by the sound of the train hom and
AHS,,, respectively. The comparison of the train hom and AHS", shows a dramatic difference bctween the areas that are impacted at specific decibel levels. By examining the 80 deeibel
contour on the two footprints it can be seen that the area-impacted by the AHS", is a fraction of the Train Horn Automated Horn System How AHSTM Connects to the Railroad AHSTh' connects
with the railroad's crossing warning system m a manner similar to traffic signal preemption connections. Typically AHSThI horns and control cabinets are mounted on their own pole assemblies.
The confirmation signal is attached to the top of one of the pole assemblies and must provide a clear line of sight to approaching trains from 1/4 mile away. Power is typically provided
by the eity. size of the 80 decibel contour produced by the train hom. Note: The noise footprints were developed with actual data collected by the Iowa DOT in Ames, IA. The AHS", footprint
is skewed because the horns were aimed at the first four cars at the crossing. In actuai installations the horns are focused as far down the roadway approach as possiblet to create a
symmetrical noise distribution along the roadway. , M _ -,Power Supplyo:'" Railroad Controls Limited 500 South Freeway Phone: (817) 820-6300 Fort Worth, TX 76104 Fax: (817) 820-6340

... »: S.J-􀁾􀀠􀁾 0-.. : ct.J.--lr 􀁾􀁾􀀠!2!?-􀁾􀀨􀁩11 􀁑􀁴􀁶􀀮􀁤􀀭􀀧􀁾􀀠... f---JS-D I :. 􀁾􀁲􀁽􀁟􀀠􀁆􀁥􀁾􀀠􀁦􀁊􀁾􀁾􀁙􀁉􀁟Jr-b.L 􀁾􀁾􀀭􀀻􀁹􀀠... 􀀭􀀭􀀭􀀭􀀭􀀭􀁣􀁦􀁴􀀭􀀭􀀮􀁥􀀮􀀮􀁶􀀮􀀧􀁾􀁟􀁻􀀮􀀯􀀢􀀭􀀭�
�􀀭􀀬􀁰􀁾􀁤􀀭􀀺􀀠(J)Y c I ... 􀀦􀁾􀁭􀁴􀀮􀁯􀀯􀁾􀁉􀀠􀀮􀁦􀀭􀀱􀁊􀀭􀁆􀁾􀁲􀀭􀀬􀁻􀁾􀁬􀁣􀁉􀀺􀁲􀁨􀀻􀀭􀀮􀀺􀁧f:t:l"!,J-,f0-j 􀁵􀀮􀀧􀁾􀁊􀀭􀁌􀀠..; [J0w -􀁴􀁌􀁾􀀠􀁾􀁊􀀠􀁾􀀠.:), , 1.51-/5d-fev"'--l't(
.,; :.. 0vlutL CL 􀁗􀁶􀁾􀁴__ J-􀀭􀁰􀀢􀁻􀀯􀁾􀁾:.: U,)(J/L-􀀡􀀯􀀱􀁢􀀧􀀯􀁷􀁦􀁾􀀠)tA-t.. 􀁾􀀭􀁾F-V;r·d? £4􀀬􀁾􀀠-hrr 􀁾􀀮􀁾􀀮􀁰􀀭􀀻􀁨􀀠dh 􀁾􀀠.; 
I! : : I I I, ! ! ) i i,I: II I' Ii 􀁾􀀢􀀺􀀠I . , j i ! 1 ; " i.: :, i /or3eJ II .MARK M. 􀁈􀁁􀁎􀁃􀁏􀁃􀁋􀁩􀁳􀁬􀁡􀁷􀁰􀁾􀁰􀁢􀁥􀁲􀀠. Former Vice President Dlln Quayle examines the 􀁗􀁡􀁹􀁳􀁩􀁤􀁾JIorns
.jluiiBg II · visit ttl RichardsOIi. Tht: system, 􀁤􀁥􀁳􀁩􀁧􀁮􀁾'to reduce train. hOruioise, was I · tested Thursday ·at a Custer RlI8drailroad. crosSing; The owner of the · Cl1mpuy
that makes the devieeis 8 friend of-Mr. Quayle's. . . ." 􀀧􀁾􀀬􀀧􀀠.'.: ' " :', ,: '" '. ", -' . ," ," , .. ' .......................... . ';' "" . ,., ' 
Wayside Horn Sound Radiation and Motorist Audibility Evaluation Prepared for: Association of American Railroads 50 F Street Washington D.C. 20001 Prepared by: MIKE FANN & Associates
Consultants in Noise & Vibration 1701 W. Northwest Highway Grapevine, TX 76051 May 24, 2000 
Wayside Horn Sound Radiation and Motorist Audibility Evaluation Executive Summary Wayside horns are a viable alternative to locomotive horns for audible warning at grade crossings. Wayside
horns have the advantage of being closer to the motorist. In addition, they have a more focused radiation pattern and produce less community noise exposure. Previous FRA studies,·2 have
been encouraging but less than totally favorable. Consequently, RCL (Railroad Controls Limited Inc.) increased the warning volume capacity and added low frequency tones, seeking more
resemblance to the classical train hom. The current RCL hom was tested on May 3, 2000 to demonstrate both dBA and one third octave bands at 22.5° angular increments. This data allows
more accurate community noise exposure forecasts and motorist audibility evaluations. The Volpe Center evaluated the wayside hom as an audible device for approaching motorists prior
to gate closure. With this perspective, they concluded that the historical hom volumes were insufficient. Consequently, RCL increased hom volume capacity in current systems by 6-10 dB.
This change alerts 99% of approaching drivers with only partial anticipation of a train event. The system is just as successful at lower volumes, if the driver is at rest behind the
gates. The wayside hom is usually applied only to gated crossings with constant warning time control. Previous installations have constant warning time control which activate gates 25
seconds prior to train arrival. Gates are fully closed in 5 seconds, forcing the cars to stop. This is 20 seconds before the train arrives. In this situation, the wayside hom is not
the primary warning device, but a secondary confirmation of train arrival. Hom audibility requires less volume because the car is at rest and closer to the hom location. The first car
and fourth cars are 16' and 61' from the hom ,respectively. In this example, the hom is audible to 99% of the population in the fourth car, with a volume of 83 dBA, outside the car.
This is 19 dB less than than maximum volume, which improves community compatibility. With stationary cars, a,W$!yside hom reference of 78 dBA at 100' is as good as a more distant train
hom with a 96 dBA reference. Although unnecessary, louder wayside hom volumes up to 92 dBA can insure warnings as gOOd as the full range of locomotive hom inventory. The focused radiation
pattern minimizes community intrusions, making it a viable alternative to louder locomotive hom warnings. Railroad HOr/! Systems Research, U.S. Department ofTransportation Federal Railroad
Administration, Report No. OOT-VNTSC-FRA-98-2, January 1999 2 Field Evaluation ofa Wayside Hom at a Highway-Railroad Grade Crossing, U.S. Department of Transportation Federal Railroad
Administration, Report No. DOT-VNTSC-FRA-97-1, June 1998. Mike Fann & Associates 1701 W. NW Hwy, Grapevine. TX 76051 (817) 442-8485 email:mfann@airmail.net 2 
Introduction The Volpe Center authored the first two references. The FRA publication "Railroad Hom Systems Research" is referenced many times, This publication provides current car noise
reduction characteristics (Insertion loss) and interior noise levels. It also provides a pivotal understanding of hom detection theory, based on driver's expectation and hom SIN values,
The same basic methodology is used to calculate the warning level inside the car and to forecast motorist response. This report in part updates those conclusions based on the most current
wayside characteristics. It also seeks to elaborate'more on the wayside horn attributes at a gated crossing with constant warning time control. The Volpe Center examined the audibility
of approaching motorists, pointing out that the hom may be the first alerting characteristic of gate activation. The hom sounds at the same time as the gates start to close. Therefore,
a driver might hear the warning before they saw the gates in a partially closed position. Their analysis of the hom is based on audible warning alone, without any synergistic contribution
from visual observations. The wayside hom application has only been applied to a crossing with constant warning time control. The electronic crossing circuitry activates gate closure,
25 seconds before the train arrives. The controls sense and account for train speed, Gates close fully 20 seconds before the train arrives. The Volpe Center worries about motorists who
stop at the gates and then drive around them without waiting for the train to pass, They determined that this motorist needs 10 seconds to accomplish that task. In this example, the
wayside hom provides an additional verification that the train is coming to encourage re-evaluation. In fact, this is the primary function of the wayside hom, The gates are always down
before the train arrives. This perspective allows a lower hom volume because the drivers are closer, more attentive, with less interior car noise. Wayside Hom Tests in Fort Worth, TX
on May 3, 2000 The current wayside hom design produced 98 dBA (100'), on May 3, 2000 in Fort Worth, TX. The test site was a large parking lot, east of IH35. Highway traffic background
noise averaged 65 dBA and 70 dBL The lot provided 600' of clear space, except for one single building located 400', 22.50 counter clockwise, off,centerline. The wayside hom was mounted
12' high on a parking lot light pole. Measurement heights are 4'. 􀁾..􀁾.. Measurements were made at 100' and 200' distances in 22,5° increments, in front of the hom. The hom was then
turned 1800 for measurements on the back side. The table below presents these sound levels not only in overall, dBA, but also in one third octave frequency bands. A type one, Quest model
1400 sound level meter provided the microphone input to a Rion Model SA 27 "!nalyzer, The microphone has recent lab certification. A Quest Model QC-20 calibrator also provided field
checks. Calibration checks included both 250 Hz and 1000 Hz and amplitudes of both 94 dB and 114 dB. ' Mike Fann & ASSOCiates 1701 W. NW Hwy, Grapevine, TX 76051 (817)442-8485 email:mfann@airmail.net
3 
The hom software sounds two longs, a short and a long. Amplitudes were consistent in level and one or two events provided data at each of the 32 measurements. The data provides current
reference amplitudes as well as typical radiation pattems. Sound Levels, dBA The current hom levels are 98 dBA at 100'. The level was 90 dBA at 200'. This result is unexpected because
it deviates from the expected 6 dB change with distance doubling. It is premature to conclude that the fall off with distance is 8 dBA, with each doubling. Reflective interference unique
to some hard surface test sites most likely causes the 2 dB difference. Reflective waves off hard surfaces can interact with sound that propagates directly to the microphone and cause
additional reductions because of phase mismatch. This condition is a function of distance, measurement height, and surface reflective characteristics. It is more likely that sound consistently
reduces by the classical 6 dB with each doubling of distance. Later calculations use this this assumption. Mike Fann & Associates 1701 W. NW Hwy, Grapevine, TX 76051 (817) 442-8485 email:mfann@airmai
l.net 4 
Wayside Hom Sound Levels 513100 I· Table 1 Orientation I dBA I 160 Hz 1 200 Hz I 250 Hz 1 315 Hz 1 400 Hz I 500 Hz 1 630 Hz 1 800 Hz 11000 Hz 11260 Hz 11600 Hz 12000 Hz f2500 Hz 13150
Hz 14000 Hz 15000 Hz @100' . 0.0· 22.5· 45.067.5· 90.0·· 112.5° 135.0157.5180.0° 202.5225.0· 247.5· 270.00 292.5· 315.0· 337.5· 360.0· dBA del del dBl del dBl dBl dBl dBl dBl dBl dBl
dBl dBl dBl dBl dBl 98.0 63,4 58.5 59.6 68.6 82.9 75.5 85.7 89.3 91,4 91.0 86.2 90.7 83.3 80.5 72.6 54.7 95.6 60.9 56.5 58.0 71,4 79.8 72.6 77.7 88.8 89.2 91.0 81.2 85.3 73.8 72.3 63.8
47.2 91.5 62.8 57.7 58.8 69.8 73.8 71.5 76.6 87.9 86.5 83.9 71.2 73,4 70.0 59.7 53.0 45.3 85.1 65.9 60.7 58.5 65.7 70.6 68,4 69.6 83.3 77.7 68.4 67.3 71.9 58.6 56.3 50.0 45,4 78.7 61,4
56.8 56.7 63.9 71.1 66.4 74.9 74.0 71,4 66.0 63.6 65.5 55.2 52.5 48.5 45.2 76.8 63.5 59.1 55,4 60.3 74.1 68.2 70.8 69.2 67.7 68.0 63.4 60.5 54.2 50.3 48.3 45.3 76.4 60.9 56.6 55.3 63.2
74.5 67.1 62.3 69.9 68.8 66.8 61.0 61.5 54.6 50.3 47.8 45.3 75.7 61.5 58.5 155.6 64.5 72.2 64.6 68,4 68,4 70.2 66.7 65.1 62.6 61.2 55,4 50.2 48.3 45.8 77.9 64.6 60.3 57.3 61.7 76.1 70.7
67.0 71.9 68.9 67.7 64.4 57.5 54.9 50.2 48.9 45.0 75.8 63.3 60.7 57.3 62.3 74.9 69.8 70.8 67.1 65,4 62.1 59.4 58.0 52.6 48.1 47.6 45.9 75.7 62.6 58.0 55.1 61.7 74.9 69.3 67.6 69.0 62.8
63,4 61.3 57.7 53.8 49.3 48.7 45.4 76.9 61.9 58.9 55.9 61,4 75.1 68.7 70.5 68.2 68.9 64.8 62.9 64.0 54.7 50.4 48.5 46.0 79.6 65.9 62.6 56:9 60.4 78.1 71.8 71.6 74.1 68.9 64.7 68.5 61.9
55.0 50.4 48.7 46.4 83.0 65,4 60.8 57.4 67.4 80.4 75.3 70.0 77.6 74.2 73.2 69.6 65.3 60,4 51.9 48.8 47.3 86.6 65.6 59.0 57.4 69.2 74.7 72.7 74.1 80.4 81.5 81.2 70.4 68.7 69.0 53.6 51.8
52.2 93.9 67.1 59.5 60.7 72.2 77.6 72.4 82.5 87.2 87,4 89.5 80.7 81.2 71.3 65.2 62.0 66.0 98.0 63.4 58.5 59.6 68.6 82.9 75.5 85.7 89.3 91.4 91.0 86.2 90.7 83.3 80.5 72.6 54.7 200' 1dBA
L160 Hz I 200 Hz I 250 Hz I 316 Hz 1 400 Hz I 500 Hz I 630 Hz I 800 Hz 11000 Hz 112&0 Hz 11600 Hz 12000 Hz InDo Hz 13160 Hz 14000 Hz 15000 Hz 􀁾􀀮􀁏􀀮􀀠22.5· 45.0· 67.5· 90.0· 112.5·
135.0· 157.5° 180.0· 202.5· 225.0° 247.5° 270.0· 􀀲􀀹􀀲􀀮􀀵􀁾􀀠315.0° 337.5· 360.0· 89.B 60.3 55.6 55.1 68.5 83.5 83.5 84.1 83.0 79.0 73.3 77.1 80.8 77.1 13.8 66.7 60.0 86.8 63.0 60.3
55.5 66.2 85.8 81.0 76.6 79,4 73,4 70.9 74.4 75.4 64.5' 60.0 54.6 47.1 83.2 70.3 63.1 60.9 66.3 83.0 76.7 77.5 76.3 66.8 64.6 65.6· 65.2 64.4 49.6 49.9 45.4 79.6 63.0 56.4 56.3 66.2
76.5 75.2 73.2 75.0 63.9 55.9 65.8 64.4 54.7 48.6 47.8 45.8 75.0 65.4 63.0 61.0 61.8 74.4 70.4 69.7 66.4 60,4 58.1 58.6 55.5 50.3 47.9 47.1 45.3 76.1 60.9 54.5 51.7 61.0 73.7 70.7 74.0
69.5 58.4 59.3 56.8 53.8 50.2 48.8 47.7 45.3 73.8 63.4 58.1 53.9 62.6 72.8 70.1 69.8 64.5 56.6 54.3 56.5 53.7 48.8 47.6 47.0 45.6 73.0 60.4 55.7 54.0 61.8 72.8 68.4 66.0 62.8 58.6 55.5
60.3 55.3 49.2 47.4 47.1 45.2 76.7 59.4 54.2 53.6 63.1 76.4 73.1 70.6 68.2 55.7 58.8 59.2 56.2 50.2 48.3 48.0 45.8 76.9 65.9 61.8 58.7 62.1 78.0 71.9 70.7 65.0 56.5 55.5 57.2 54,5 50.3
47.9 47.7 44.4 .75.0 59.5 56.1 53.3 59.8 75.9 71.0 65.1 63.7 55.0 55.7 58.9 54.7 50.6 47.5 47.6 45.2 76.2 62.7 60.1 . 54.2 63.2 74.9 71.2 72,8 67.5 56.1 58.3 60.9 60.7 52.8 48.9 48.3
45.5 75.7 68.2 64.5 63.4 63.5 76.2 70.5 66.0 66.1 61.1 58.7 60.4 58.9 53.1 49.6 48.1 45.9 80.5 63.8 58.5 56.6 65.8 78.4 77.6 72.3 73.2 68,8 67.0 65.8 64.2 56.4 51.2 47.7 46.3 83.6 64.0
59.4 57.6 65.2 81.2 77.5 77.7 77.3 71.1 70.4 72.1 67.7 62.6 53.2 50.3 45.8 87.1 60.7 53.0 56.4 67.7 78.9 76.0 83.8 76.9 72.5 76.0 80.4 78.2 66.3 58.1 57.7 47.4 89.8 60.3 55.6 55.1 68.5
83.5 83.5 84.1 83.0 79.0 73.3 77.1 80,8 77.1 13.8 66.7 60.0 Mike Fann & AsSOCiates 1701 w. NW Hwy, Grapevine, TX 76051 (817) 442-8485 email:mfann@airmail.net 5 
Frequency Content Figure 1 presents the hom frequency content. The chart shows tonal amplitudes in one third octave band frequencies. There are significant differences in this chart
from the frequency spectrum found in Figure 11, page 32 in "Railroad Hom Systems Research". Figure 1 includes a new low frequency tone. In addition, the levels are 10 dB higher and more
closely resemble the train hom Signature. This makes the frequency spectrum similar, in both frequency content and amplitude to a train hom. RCL Wayside Hom Frequency Spectrum on Centerline
at 100' Distance Figure 1 100.0,.--------------------, ::r 90.0····" co :!:!. 􀁾􀀠80.0 ! '" en en ! 70.0 a. 'C I:! ::I o (/) 60.0 50.0 -1-......_-_......._-____-___-_............ 􀁾􀁾􀁾􀁾􀀣􀀣􀁾􀀣􀀣􀁾
􀀣􀀣􀀣􀀤􀀣􀀮􀀣􀀠v v " '" " 'P ']) ." 1>1 VJ Frequency (1/3 Octave Band Center Band, Hl:) A Union Pacific mainline track was located:1000' to the west of the test site. Several trains
passed during several hours of testing,.,.blowing the hom at grade crossings. The subjective resemblance to the wayside hom is remarkably similar. Radiation Patterns The physical characteristics
of this warning device limit efficient radiation at frequencies below 500 Hz. Figure 1 infers that radiation is most efficient at frequencies around 1000 Hz. The wavelength of 1000'
is approximately l' and has directional tendencies. This is beneficial for limiting side radiation and minimizing community intrusions. Mike Fann & Associates 1701 W. NW Hwy. Grapevine,
TX 76051 (817) 442-8485 email:mfann@airmail.net 6 
Figure 2 shows the change in levels with orientation at 200'. The shape is symmetric in front of the hom. Site background noise causes the symmetry deviation on the back side. The lower
levels were not consistently 10 dB above the highway noise on the site. RCL Hom Radiation Patterns Sound Levels (dBAl at 200' Distance Figure 2 Table 2 lists the change in noise level
with centerline orientation. The change is 3 dB, 22.5° either side of centerline. It progressively reduces another -3 dB with successive 22.50 increment, up to 90· and then is fairly
constant in level behind the hom. Noise Reductions with Changes in Orientation for Hom centerline Table 2 Orientation 22.5· 45· 67.5· 90· 112.5· 135· 157.5· 180· 202.5° 225· 247.5· 270·
292.5" 315· 337.5" NOise Reduction 3 dBA 6.6 dBA 10.2 dBA 14.8 dBA 13.7 dBA 16 dBA 16.8 dBA 13.1 dBA 12.9 dBA 14.8 dBA 13.6 dBA 14.1 dBA 9.3 dBA 6.2 dBA 2.7 dBA The hom level is substantially
quieter on the back side. Levels reduce approximately 15 dB and are more omnidirectional. Mike Fann & Associates 1701 W. NW Hwy, Grapevine, TX 76051 (817) 442-8485 email:mfann@airmail.net
7 
Approaching Motorist Warning Detectability An approaching motorist will hear the waming if there is sufficient amplitude based on car interior noise and the motorist's attention level.
The FRA publication, "Railroad Hom Systems Research" presents a methodology for making this determination. The concept of tonal detection as a function of background noise level has
been studied for many years. H. Fletcher published the concept of critical bandwidth in 1940.3 Critical bandwidth recognizes that the human ear acts like a filter to hear a specific
tone. Only a limited bandwidth of background noise tends to mask or cover up that tone. Sanford Fidel! made the concept more applicable to wayside homs in his publication, "Effectiveness
of Audible Warning Devices on Emergency Vehicles"' He pointed out like Fletcher before, that audibility occurs with sufficient hom signal at only one tone (one 1/3 octave band). Other
worn in detection theory led to Figure 4 on page 24 of "Railroad Hom System Research". Figure 3 below is a reproduction. Horn Detection Probability vs SIN Figure 3 15.00 ...--------------,
:::r III..,--10.00.\-_-__-__-__-_..... 10.00 ........ 5.00 ............................... -5.00 ...... 000 0 000 0 m m N M 􀁾􀀠􀁾􀀠􀁾􀀠􀁾􀀠w m m m 000 0 dod 0 0 ci Hom Detection Probability
1--+-0.9 Perceived Train Probability -0-0.5 --0.1] 'H. Fletcher, Auditory Pattems, Revs. ofMod. Phys., 12:47-65 (1940). • Potter, Re., Fidel], S.A, Myles, M.M., and Keast, D.N. Effectiveness
oJAudible Warning Devices on Emergency Vehicles. Report No. DQT-TSC.QST-77-38, August 1977. Mike Fann & ASSOCiates 1701 W. NW Hwy, Grapevine, TX 76051 (817)442-8485 email:mfann@airmaiLnet
8 
Perceived train probability is defined as the motorist's expectation of a train. The motorist's previous driving. experience may formulate an expectancy that he will see a train. This
is similar, if not the same as the probability that the driver will actively look and listen for a train. The lower curve shows the expected result if the motorist looks and listens
for a train, 9 out of 10 times. The results are similar to lab detectability tests when the subject expects a tone. Lab detection subjects routinely identify tones that are lower in
level than the background noise. Figure 3 forecasts that this driver would hear the waming half the time if the hom signal inside the car were 5 dB less than the background noise. This
is a -5 SIN (signal to noise). He would hear it 95% of the time if the hom signal were only 1 dB above the background noise level. A preoccupied driver would actively look and listen
for the train less often. Even so, they would hear the waming 50% of the time, with a +0 SIN (anyone 1/3 octave band), if they only anticipate the train half the time. Table 3 is a sample
calculation of the hom SIN value. It is the same format used in Appendix E of "Railroad Hom Systems Research". The first tabular line item is the hom level from testing on May 3, 2000.
Item 2 is the level at 358'. The calculation uses the classical change in distance of 6 dB with each doubling of distance. This distance is suggested as the necessary warning distance
for a car traveling 40 mph (Table 12, page 34)' for a wayside hom application. The car insertion loss is a measure of the car shell noise reduction characteristics. The values in item
3 are from Figure C-11 of Appendix C1 and are an average of seven vehicles tested. Item 4 determines the hom level inside the car by subtracting the car insertion loss from the outside
hom level. The car interior noise is also an average of seven tested vehicles (Figure C-2)' . It is a classic shape with higher amplitudes at lower frequencies and a gradual reduction
in amplitude with increased frequencies. Vehicle speed for interior noise is 30 mph with no ventilation fan operating. Example Calculation of Motorist Horn SIN Values Table 3 1.) SJlectrum
values from 513100 testin Freq Hz 200 250 315 400 500 630 800 1000 1250 1600 2000 2500 160 @100' 63 59 60 69 83 75 86 89 91 91 86 91 83 dBl 3150 4000 5000 81 73 55 2.) Calculating the
horn level at 358' uses the levels at 100' and adjusts them for distance. This adjustment is 20"og(100/358)=-11 Subtracting 11 dBL from item 1 ) Freq Hz 160 200 250 315 400 500 630 800
1000 1250 1600 2000 2500 3150 4000 5000 @440' 52 dBl 48 49 58 72 64 75 78 80 80 75 80 72 70 62 44 3.) Car Insertion loss' These values will be subtracted in the next line from item 2.)
Freq Hz 160 200 250 315 400 SOD 630 800 1000 1250 1600 2000 2500 3150 4000 5000 Il 18 dBl 20 18 18 22 26 29 29 27 30 34 32 34 34 34 35 Mike Fann & Associates 1701 W. NW Hwy, Grapevine,
TX 76051 (817) 442-8485 email:mfann@airmail.net 9 
4.)Homlevel inside the car. Item 2)-item 3) Freq Hz 160 200 250 315 400 500 630 800 1000 1250 1600 2000 2500 3150 4000 5000 interior hom 34 dBL 28 31 40 50 38 46 49 53 50 41 48 38 36
28 9 5.) Average interior car noise F,'!eq 􀀭􀀮􀀭􀀮􀀧􀀮􀁾􀀠Hz 160 200 250 315 400 500 630 800 1000 1250 1600 2000 2500 3150 4000 5000 Interior noise 61 dBL 59 58 56 53 51 47 45 44 42
40 36 34 31 30 26 Comparison of the horn interior level with the car noise shows a positive signal to noise in seven consecutive bands from 800 Hz -3150 Hz. Figure 3 shows that a 11.3
dB signal to noise in the 2000 Hz, one third octave band assures that 99.9% of the drivers hear the warning with only a 50% train expectancy. Even with this conservative assumption that
the driver only looks for the train one half the time, 99.9% of motorists should hear the warning. Stationary Motorist at Gated Crossing Audibility At a gated crossing with constant
warning time control, the wayside hom activates at the same time the gates start to close. Gate closure begins 25 seconds prior to train arrival and takes 5 seconds to close fully. Gates
are down 20 seconds prior to train arrival. In this situation, the wayside hom is not the primary warning device, but is a secondary confirmation of train arrival. Hom audibility requires
less volume because the car is at rest and closer to the hom location. The first car is 16' from the hom instead of 358' away traveling 40 mph. The fourth car in line is 61' away. This
calculation, in contrast to the last example, begins with the SIN necessary in anyone third octave band and works backward to determine the necessary exterior hom levels. Item 1 is the
average interior car noise at 30 mph. This includes tire noise which is too high for a stationary car. However, it is used for consistency. Example Calculation of Necessary Hom Volume
for Stationary Motorist Table 4 1.) From Figure C-2 the avera e interior noise level is Freq Hz 160 200 250 315 400 500 630 800 1000 1250 1600 2000 2500 3150 4000 5000 interior 61 59
58 56 53 51 47 45 44 42 40 36 34 31 30 26 Mike Fann & Associates 1701 W. NW Hwy, Grapevine, TX 76051 (817) 442-8485 email:mfann@airmail.nel10 
interior 68 66 65 63 I 60 I 58 I 54 I 52 I 51 49 47 43 41 38 37 33 3.) Car insertion loss These values Will be added in the next line to item 2.) to obtain exterior hom level requirements
Freq Hz 160 200 250 315 400 500 630 800 1000 1250. 1600 2000 2500 3150 4000 5000 IL 18 20 18 18 22 26 29 29 27 30 34 32 34 34 34 35 4.) AddinQ 3.) + 2 . determines the exterior hom requirements
for the fourth car in line at 61' distance. Freq Hz 160 200 250 315 400 500 630 800 1000 1250 1600 2000 2500 3150 4000 5000 @61' 86 86 83 81 82 84 83 81 78 79 81 75 75 72 71 68 5.) Hom
level needed at laO', adjusts for distance correction. Adjustment is 20*log(611100}= -4.3 dB Freq Hz 160 200 250 315 400 500 630 800 1000 1250 1600 2000 2500 3150 4000 5000 @100' 81
82 78 77 78 79 79 77 74 75 77 71 70 68 67 64 6.) 5/3100 testing at 100' Freq Hz 160 200 250 315 400 500 630 800 1000 1250 1600 2000 2500 3150 4000 5000 @100' 63 59 60 69 83 75 86 89
91 91 86 91 83 81 73 55 Wayside volume headroom Item 2 calculates the necessary hom signal inside the car by adding 7 dB to each of the interior car noise levels. Figure 3 shows that
this increase is sufficient to alert 99% of the drivers who listen 9 out of 10 times. Item 4 calculates the necessary hom level outside the car and Item 5 calculates the corresponding
reference distance at 100' from the hom. This is compared to the maximum levels tested on 5/3100. Item 7 shows that the maximum levels are 19.6 dB higher than they need to be for alerting
the fourth driver in line. This is good news to residents immediately. at the crossing. At gated crossings with constant warning time control, a volume of 78 dBA@100' (98 dBA -19.6 dBA)
is sufficient. This 78 dBA reference level produces 83 dB outside the carbecause the fourth car is closer at 61'. The lower volume maximizes community compatibility without sacrificing
warning effectiveness. Mike Fann & ASSOCiates 1701 W. NW Hwy, Grapevine, TX 76051 (817) 442-8485 email:mfann@airmail.net 11 
Train Horn Comparisons With the gates down, the wayside hom is as effective as the more distant train hom. Table 4 demonstrates that 83 d8A outsidethe car is sufficient warning. This is achieved with a wayside hom reference of 78 dBA at 100'. Table 5 shows the corresponding train distance from the crossing, with the gates fully
closed, 20 seconds prior to train arrival. It also shows the train hom level outside the cars for different volume train horns. Train Horn Levels at Fourth Car: 20 Seconds Before Crossing
Table 5 Train speed 20 mph 22 mph 24 mph 26 mph 28 mph 30 mph Train Distance to Crossing 587' 645' 704' 763' 821' 880' 96 dBA train hom 81 dBA 80 79 78 78 77 104dBA train hom 89dBA 88
87 86 86 85 108dBA train hom 93dBA 92 91 90 90 89 111dBA train hom 96dBA 95 94 93 93 92 Wayside Hom 82dBA 82 82 82 82 82 The wayside hom is as good as the FRA required train hom certification
(96 dBA @100'). Although the lower wayside horn level is sufficient, higher level adjustment can match and exceed the higher train hom inventory. Wayside Hom Reference Volume (100')
Necessary to Match Train Hom Volume Levels 20 Seconds Before Crossing Table 6 Train Hom Level (100') Wayside Hom (100') 96dBA 77dBA 104 dBA 85dBA 108dBA 89dBA 111 dBA 92dBA Table 6 presents
corresponding wayside hom volumes that match the level produced by different volume train horns, 20 seconds before train. arrival. The wayside hom achieves the same result at a lower
volume because the 􀁦􀁯􀁵􀁾.. car is only 61' away from the hom instead of the 587' comparative distance from the train hom traveling 20 mph. Conclusions Wayside hom applications have
had favorable community responses at several installations. The maximum hom levels demonstrated on May 3,2000 are 6-10 dB louder than previous installations. Although unnecessary, this
increased volume is available, if desired. The focused radiation patterns maximize residential compatibility. This system is a good balance between adequate warning of motorists and
minimizing community noise levels. . Mike Fann & Associates 1701 W. NW Hwy, Grapevine, TX 76051 (817) 442-8485 email:mfann@airmail.net12 
A SAFETY EVALUATION OF THE RCL AUTOMATED HORN SYSTEM A Report from the Texas Transportation Institute by Stephen S. Roop, Ph.D. Texas Transportation Institute Rail Research Texas A&M
University System College Station, TX 77843-3135 May, 2000 
List of Tables Table 1. Wayside Hom Temporal Sequence .............................................................................. 3 Table 2. Frequency ofFalse Activations and Violations
for Two Warning Devices ..................... 6 Table 3. Frequency of Violations for AHS in 2000 Relative to Locomotive Hom in 1995 ........... 7 Table 4. Frequency ofViolations for
AHS in 2000 Relative to AHS in 2000 ............................... 7 Texas Transportation Institute 11 Rail Research Center 
Table of Contents Background ......................................................................, ....................................................... 1 Problem Statement ......................
............................... , ............................................................. 3 Study Objective .....................................................................................
.................................... 4 Evaluation ofAHS at the Tenth Street Crossing .......................................................................... 5 Results .............................
.......................................................................................................... 5 Conclusions & Discussion .................................................................
...... ' ........, ........................ 7 Texas Transportation Institute Rail Research Center 
Background Safety at highway-rail intersections (HRI's) has been dramatically improved since the 1970's through concerted public and private efforts. According to the Bureau ofTransportation
Statistics (BTS) accidents, injuries, and fatalities decreased between 1975 and 1995, by 38%, 49"10, and 36%, respectively, even in light ofincreased traffic on both roads and rail.
Ton-miles of freight increased by approximately 57% during the same period (BTS). This feat was accomplished through a multi-pronged attack on both grade crossings and drivers. The Federal
Highway Administration (FHWA) estimates that between 1974 and 1995, the investment of over $3 billion in grade crossing safety for nearly 30,000 projects helped save almost 9,000 lives
and prevent nearly 40,000 accidents. Federal funding, including the Section 130 Program, allowed most states to install active warning devices at high-priority crossings at a fairly
steady rate. Coupled with public awareness programs like Operation Lifesaver, this one-two punch has proven that cost-effective safety gains can be made at HRI's. Importantly, the improved
safety record at HRI's has been achieved largely without much i!U1ovation in the presentation ofwarning systems themselves. Standard lights and gates remain the front line in safety,
augmented by advanced warning signs, pavement markings, and the locomotive hom. This last element in the warning system arsenal, the locomotive horn, has been shown to be effective by
its selective omission. In a rather unique and unintended demonstration ofwarning system efficacy, "whistle bans" in some communities have resulted in increases in accidents. In 1984,
Florida imposed a whistle ban between the hours of 10pm and 6am on the Florida East Coast Railroad in cities along its operating corridor. In a subsequent study ofthe effects ofthe ban,
the Federal Railroad Administration (FRA) reported that accidents increased by 84 percent across the 2,000 impacted intersections. In spite ofincreased accidents, however, Florida counties
choose to maintain the whistle ban. The central issue regarding whistle hans revolves around the intrusive and very disruptive impact oflocomotive horns on the surrounding community.
Federal regulations (CFR 49 Part 229.129) ensure that the volume ofthe hom is sufficient to reach motorists on roadways perpendicular to the trains and well enough in advance ofthe intersection
to be able to respond safely to the train (i.e., stop). Herein lies the dilemma: to reach motorists at the proper angle to the HRI with enough time to provide foz: adequate stopping
distance, the hom has to be loud. The intensity of the hom allows the sound to reach far beyond a desirable range, impacting everyone, whether in a vehicle or not. Community critics
suggest that the locomotive hom works too well and alerts everyone, day or night, proximate to the intersection or not. The FRA and the railroads see the locomotive hom as an effective
means ofalerting motorists to the immediate presence ofa train and consider the safety benefits gained worth the intrusive noise. Tex.tJ.> Transportation lnstituk 1 Rail Research Center

Federal regulations require the train horn to be 96 db at a centerline point 100 feet in front ofthe locomotive, and four feet above the track. This intensity is judged to be sufficient
enough to reach down intersecting roadways, penetrate any barrier presented by the automobile itself, overcome other internal or external environmental auditory competitors, and alert
the driver of the train's approach. Most ofthe time it seems to work, although as vehicles become better insulated, the challenge of alerting motorists increases. Unfortunately, reaching
other people who happen to be in the vicinity seems far easier. An innovative solution to this problem supported by some is a stationary horn mounted at the grade crossing. The stationary
horn or automated horn system (AHS) is sounded in place ofthe train horn. Activated by the same mechanisms that trigger the active warning system, the AHS is designed to direct sound
down the roadway rather than down the track. In this way, horns with less overall intensity may be able to deliver a more effective warning to vehicle operators approaching an HRI. The
Gering, Nebraska Study A recent study ofthe automated horn system in operation in Gering, Nebraska, suggests that the AHS is effective in warning motorists (Volpe, 1998). In fact, with
the AHS in place, motorist violations were shown to initially decrease over the rate seen with standard locomotive horn warnings. The Volpe report also examined the community response
to the AHS relative to locomotive horns, performed some acoustic analyses, and observed driver behavior at the intersections where the AHS was installed. The results ofthe study suggest
that the AHS was an effective substitute for the locomotive horn in warning motorists. The AHS evaluated in Gering in 1995 consisted ofa Federal Signal Selectone horn (model 302GCX),
a tone module (Federal Signal Universal Tone Module 13) containing the sound recording of an air horn and a control board which received the signal from the track circuitry and activated
the horn. Mounted on the top ofthe horn case was a Federal Signal strobe light (model 131 ST) that provided a visual confirmation for the locomotive engineer that the wayside horn was
appropriately sounding. A detector installed inside the horn case activated the strobe light ifthe horn emitted a signal ofat least 80 dB. Ifthe wayside horn was less than 80 dB, the
strobe light remained offand the engineer was instructed to manually blow the train horn. The system was subsequently enhanced with a digital recording which more closely resembles the
3 -tone sound of a locomotive horn. This enhancement was prior to the data collection period in March and April, 2000. The activation ofthe wayside horn was tied to the same circuitry
that activated the crossing gates, flashing lights, and crossing bells. Gate descent began approximately two seconds after activation Texas Transportation Institute 2 Rail Research Center

of the flashing lights, bells and wayside hom When the track circuitry activated the AHS, the system repeated the sequence shown in Table I until the train reached the grade crossing.
When the train reached the grade crossing the wayside horn sounded for five seconds. The system was designed to produce a sound pressure level of 114 dB at 10 feet and 98.9 dB at 50
feet. Table 1. Wayside Hom Temporal Sequence Sequence 2 3 4 Duration On (s) 3.0 3.0 15 3.0 Duration Off (s) 1.5 1.5 1.5 1.5 (from Volpe, 1997) In the Volpe report, motorist violations
at grade crossings were described as Type I or Type 2 violations. Type I violations were defined as those where the motorist is observed to drive through the grade crossing after gate
descent is initiated, but before the gates were completely down. Type 2 violations were those where the driver proceeded through the crossing after the gates were completely down. In
Gering, Type I violations were reduced by a statistically significant amount with the AHS over the rate observed with a standard locomotive hom. There were no clear differences between
the locomotive horn and the AHS relative to Type 2 violations, perhaps in part since motorists are less likely to commit Type 2 violations in any event. Problem Statement "Whistle-bans,"
because ofthe negative safety ramifications, present a problem for railroads and any public agency responsible for the well-being ofthe traveling public. Currently, the Federal Railroad
Administration, through its rule-making process, has plans to recommend five safety measures that "fully" compensate for locomotive horns and may therefore be substituted under whistle-ban
conditions. These supplementary safety measures (SSMs) are: four -quadrant gates photographic enforcement systems Texas Transportation InstiJute 3 Rail Research Center 
median barriers I-way streets temporary closure (e.g., nighttime closure) Further, under the proposed rule, alternative safety measures (ASMs) may be employed in combination with SSMs
to "fully compensate for the absence ofthe audible warning provided by the locomotive hom." The ASMs include: variations of SSMs variations of SSMs long-tern programmatic law enforcement
efforts and initiatives, and targeted public awareness efforts and initiatives Thus, under the condition of a local ordinance banning locomotive horns, it is proposed that one or more
ofthese sanctioned measures may be employed to compensate for the loss ofthe auditory warning. There are no plans to include the AHS as one ofthese measures due to lingering reservations
about the long-term effectiveness of the system. The principal issue, therefore, seems to focus on the credibility of the AHS warning for motorists -do motorists learn that the AHS is
just a device and not really a train and thus become more likely to disregard it, with a corresponding increase in the likelihood of accidents? It is not suggested by proponents ofthe
AHS that it is necessarily superior to the locomotive hom as a warning to motorists, but rather that evidence to date strongly indicates that the system is as effective as a locomotive
hom system in alerting motorists to the potential hazard at an HRl and therefore should be included among the array offully compensatory systems listed above. Study Objective The objective
ofthis evaluation is to revisit the AHS installation at the Tenth Street location in Gering to assess the level of driver compliance with the warning system after approximately six years
of operation. Initial AHS implementation was in July of 1994. The original posttest period was from May 24, 1995 to October 22, 1995. Data for this follow up evaluation was collected
for 16 days from March 25,2000 to April 9, 2000. TTl was engaged by RCL to examine the data collected at the site and report on the observed rate of driver compliance (Type 1 and Type
2 violations) with the AHS stilI in place. Evaluation of AHS at the Tenth Street Crossing Texas Transportation Institute 4 Rail Research Center 
RCL used equipment provided by Transit Surveillance Systems, Inc. to video traffic in both directions at the Tenth Street crossing. Each activation ofthe track circuit mechanism controlling
the warning system (lights, gates, and AHS) also activated the digital video system and recorded the warning system behavior (lights and gates) as well as the behavior ofmotorists in
both lanes oftraffic on the approach to the crossing. The recording system continued in operation until the train had fully occupied the HRL The collected digital video was stored on
a computer for later analysis. The collected data was delivered to TTl for processing and analysis in early May, 2000. TTl evaluated the behavior ofmotorists under the condition ofextended
exposure to the AHS at the Tenth Street crossing in Gering, Nebraska by recording Type 1 and Type 2 violations ofthe warning systems. The motorists in the vicinity ofthe Tenth Street
crossing have been exposed to the AHS for over five years and thus the question ofcentral importance to this evaluation is, "Do motorists, after extended exposure to the AHS, continue
to heed the warning systems at the Tenth Street crossing at a rate which is at least as compliant as with the locomotive hom and thus may be considered as a fully compensatory system?"
The collected digital video data was scored by trained observers at TTl's facility in College Station, Texas. Rated violations were verified by both a second and third observer to ensure
the accuracy of scoring. Appropriate statistics were used to assess the rate of violations at the target crossing during the post-posttest phase relative to that recorded during pre
and post test by Volpe researchers. Results TTl evaluated 826 digital video records from the Tenth Street HRI in Gering, Nebraska. Of these, 815 observations were included in the analysis.
Eleven activations ofthe recording equipment were omitted and scored as "false activations" due to no observed train activity at the intersection. The intersection tallied approximately
50 trains per day throughout the data collection period. Volpe's 1997 report defines a Type 1 violation as, "vehicle went through the grade crossing during gate descent" and a Type 2
violation as, "vehicle went through the grade crossing after gate descent." These criteria were applied to the current evaluation to ensure consistency and allow meaningful conclusions
to be drawn from the results. The 1997 Volpe study ofthe AHS in Gering, Nebraska showed that Type 1 violations decreased following the introduction ofthe system at two roadways. Type
2 violations were not statistically different between the two systems (i.e., locomotive hom and AHS). It should be noted that Texas Transportatiolllllstitute 5 Rail Research Center 
Volpe pooled the data from two intersections, the Tenth Street crossing and the Country Club Road, to derive the following table (Table 14, page 40, Volpe, 1997), which is reproduced
here for comparative purposes. The Volpe report also evaluates "time to collision," which measures how far away the train is from the grade crossing when the motor vehicle is in the
intersection. They found no significant difference in this measure between the two systems and, therefore, we are not reconsidering this measure in the current evaluation. The Volpe
report also examines the frequency offalse activations between the two systems, which is a function oftrack circuitry and not warning system and thus is omitted from the current evaluation
as well. Table 2. Frequency of False Activations and 􀁖􀁩􀁯􀁬􀁡􀁾􀁩􀁯􀁮􀁳􀀠for Two Warning Devices Actual Frequency Frequency/IOOO Trains Chi-square Significance Value Level* Train Wayside
Train Wayside False Activations 53 41 21 10 10.50 .0012 Type 1 Violations 48 35 19 9 11.22 .0008 Type 2 Violations 4 18 2 5 3.31 .0688 * Critical Value at 1 degree offreedom = 3.84 (from
Volpe, 1997, Table 14, page 40) The data presented above, specifically for Type 1 violations, shows the effectiveness of the AHS relative to the locomotive horn across a combined 6,481
train events. The differences observed suggest that, at least initially, the AHS may be more effective in alerting motorists ofoncoming trains. The lack ofstatistical difference between
the two systems for Type 2 violations suggests that the two systems perform equally well. Table 3, below, presents data from the current post-posttest period relative to the pretest
data collected by Volpe. This allows an indirect comparison ofthe AHS after a lengthy operational period with the baseline violation rate seen at the Tenth Street site in 1995. The results
show that, while Type 1 violations with the AHS have risen over the rate seen following system implementation, they remain approximately on par with the rates seen with the locomotive
hom. The statistical analysis indicates no significant difference. Table 3. Frequency of Violations for AHS in 2000 Relative to Locomotive Horn in 1995 Texas Transpottotion Institute
6 RIlil Research Center 
Actual Frequency Frequency/lOOO Trains Chi-square Significance Value Level* Train Wayside Train Wayside Type 1 Violations 48 15 19 18.4 .0062 .96 Type 2 Violations 4 0 2 0 1.28 .27 *
Critical Value at 1 degree offreedom =3.84 A comparison ofthe AHS in 2000 with the same system in 1995 (Table 4) shows that Type 1 violations are higher now than were observed in the
original posttest period. It must be reemphasized that this increase in Type 1 violations is an increase in the frequency over the depressed rate observed after system implementation
and not an overall increase. Table 4. Frequency ofViolations for AHS in 2000 Relative to AHS in 2000 Actual Frequency Frequency/1000 Trains Chi-square Value Significance Level* Wayside
1995 Wayside 2000 Wayside 1995 Wayside 2000 Type 1 Violations 35 15 9 18.4 5.83 .015 Type 2 Violations 18 o 5 o 3.74 .06 * Critical Value at 1 degree offreedom = 3.84 Conclusions & Discussion
TTl's evaluation ofthe AHS data at the Tenth Street highway-rail intersection from March and April, 2000 in Gering, Nebraska suggests the following conclusions: 1. The AHS appears to
be, after almost 5 years ofoperation, an effective alternative to the locomotive horn at the Tenth Street crossing in Gering, Nebraska, with a violation rate no greater than that observed
during pretest monitoring. Texas TransportatWn Institute 7 Rail Research Center 
2. The observed reduction in Type 2 violations at this site may even indicate that the AHS is a higher fidelity warning system than the locomotive horn, although examining only one site
makes broad generalizations difficult. Speculation regarding the initial drop in Type 1 violations following system implementation in 1995 carmot be substantiated without further study
ofthe phenomenon, but it may be due to the greater "delivered" decibel level found with the AHS. An understanding ofthe affects ofdistance and physical obstructions on auditory intensity
may help explain the effect. With distance, the diminished auditory intensity ofa locomotive horn is a cue to the motorist, signaling the relative remoteness ofthe train. For very low
intensities at grade crossings, this remoteness translates into time and thus a perceived safety margin for drivers. As the intensity increases, the perception of closeness ofthe source
and "less time" for traversing an HRI heightens motorist vigilance. This intuitively obvious relationship helps explain the effectiveness of the train horn as a warning mechanism. The
distance-intensity effect may also explain why this warning strategy may break down from time to time, not always serving the motorist well, as environmental obstructions alter the locomotive
horn intensity and thus may alter the motorist's perception ofsource distance and safety margin. Better insulated vehicles, loud stereos, buildings, trees, and other obstructions may
contribute to the non-linearity ofthe distance-intensity cue provided by the horn. In Gering, Nebraska, after installation ofthe AHS, motorists were alerted to train presence by a higher
intensity horn, accompanied by an understandable perception ofsource proximity. The observed behavior, perhaps, indicates that motorist's perception ofthe closeness ofthe source led
to safer driving at the HRI and a significant reduction in Type 1 violations. It could be further speculated that as motorists became experienced with the AHS, they learn that the distance-intensity
cue is now a different type discriminator; one clearly associated with train presence, but no longer a good indicator oftrain distance. This uncertainty leads more motorists to stop
rather than risk traversing the HRI. In fact, this cue to train distance has been replaced by activation ofthe warning system itself, which motorists learn precedes the train by a fun
20 to 30 seconds. Motorists witnessing system activation may therefore be the only drivers likely to risk a hurried crossing ofthe HRI-not unlike motorist behavior at most active HRIs.
The fuct that Type 1 violations at the Tenth Street crossing rebounded over time to locomotive horn levels is not seen by the author as indicative ofa system weakness, but rather as
confirmation that the AHS is an effective alternative to locomotive horn systems. Were the Type 1 violations in March and April, 2000 significantly higher than pretest locomotive horn
levels in 1995, serious reservations concerning system effectiveness would have to be stated. This is particularly true Texas Transportation Institute 8 Rail Research Center 
given the high level offalse activations seen at this busy site, both in 1995 and again in the spring of20oo where motorists could be expected to have questions about the reliability
ofthe warning they receive, In summary, the AHS at the Tenth Street crossing in Gering continues to be effective as an alternative to the more disruptive locomotive hom. The system has
been in place for almost six years at a site that is very heavily traveled (50 trains per day), It appears the measures of effectiveness, i.e" Type I and Type 2 violations, employed
to assess every other SSM and ASM, indicate that the Automated Hom System is an effective alternative to the locomotive hom in warning motorists of the proximity ofa train, Ancillary
questions posed by some concerning factors beyond bottom-line system effectiveness, such as Doppler effect cues or hom directionality and intensity, seem to be holding the AHS to a standard
different than that applied to other SSMs and thus appears unwarranted given the performance ofthe system in Gering. Texas Transportation InstitJlte 9 Rail Research Center 
IMPROVE THE QUALITY OF LIFE IN YOUR COMMUNITY Railroad Controls Limited is proud to offer an innovative railroad signaling device that significantly improves safety for motorists and
pedestrians at railroad-highway grade crossings while dramatically reducing the amount of noise pollution created by train horns along rail corridors in populated areas. This product
is called 􀁁􀁈􀁓􀁾􀀬􀀠the Automated Horn System. WHAT IS AHS™? AHS" is a stationary horn system, which is actuated by the rail roadhighway grade crossing signal warning system. AHS'"
is mounted at the crossing, rather than on the locomotive, in order to deliver a longer, louder, more consistent audible warning to motorists and pedestrians while eliminating noise
pollution in neighborhoods for more than one-half (1/2) mile along the rail corridor. 140 120 "0 {l100 (j) 80 􀁾􀀠fI) 60 􀁾􀀠<:.> 40« 20 0 >80 >85 >90 >95 Decibels riiiTrairi Rorns .AHSI
THE TECHNOLOGY AHS'" is designed to sound like a train horn. The tone modules in the AHS'" horns were digitally recorded from an actual locomotive horn. Upon receipt of the signal from
the railroad's track circuit warning system AHS· mimics the train horn warning by cycling through the standard railroad whistle pattern. This pattern continues to be repeated until the
train reaches the crossing. Once the train has entered the crossing AHS'· stops sounding its horn. TRAIN OPERATIONS When a train activates the crossing signal system, AHS" activates
its horns. When the internal fail safe detector determines the horns are working properly, it actuates th(, .J interconnected confirmation 􀁳􀁩􀁧􀁮􀁡􀁬􀀺􀀧􀁾􀀠When the locomotive engineer
sees the appropriate confirmation signal he will not be required to sound his horn unless he detects an unsafe condition at the grade crossing. Coordination with the railroad operating
company is essential since AHS'" is directly connected to the railroad's crossing signal-warning system. Additionally, the railroad operating company must issue instructions to their
train crews regarding the sounding or non· sounding of the train's hom. 
Ames, Iowa Study of Residents Impact on Quality of Life 􀁾􀀠􀀢􀀧􀀬􀁾􀀬􀁾ft I 􀁾􀀠􀁾􀁾􀀠o 􀁾􀀠z Z rlllll Train Horns • AHS] ",fHAT THE AMES, IOWA RESIDENTS SAY:, <? 'We had thought about
selling our home because the trains bothered us so much. Then, Glory be to God, you installed the automated horns and we have a new life." "The automated horns are a very positive improvement
for the neighborhood, ... take the next step and provide automated horns at all crossings in town'" <? ''This is the best thing the city has ever done to increase the quality of life
in the residences." <? "We can think of nothing in 18 years of residence that has so much improved our quality of life." E:J RCL RaIlroad Controls L!m1ted Railroad Controls Limited 500
South Froeway Fort Worth. TX 76104·3504 Phone (817) 82()..6300 Fax (817) 820-6340 www.railroadcontrols.com Railroad Controls Limited AHS™ Automated Horn System* by Railroad Controls
Limited 'Patent Pending