1J OJ1jj1J] ..JJJjj11IJ _J1 J Design Report for Belt Line 􀁒􀁯􀁡􀁾􀁾􀁻􀀡􀀡􀁾􀁬􀁬􀁡􀁳 Parkway I -􀀯􀁾􀀭􀁟􀀯􀀧􀀭􀁾􀀭􀀺􀁾􀀺􀀺􀀺􀁃􀀺􀀻􀀺􀀺􀀺􀁉􀀺􀀬􀀺􀀧􀀻􀀧􀁾􀁡􀀺􀀺􀀻􀀧􀀺􀁾􀀭􀀺􀁮􀀺􀀺􀀭􀀭􀀭􀀭􀀧􀀭􀀭
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y-=--=---___ Prepared by BARTDN-ASCHMAN ASSDCIATES. INC.
II i . jI!i iI II DESIGN REPORT FOR BELT LINE ROADIDALLAS PARKWAY INTERCHANGE PREPARED FOR Town of Addison PREPARED BY Barton-Aschman Associates, Inc. October, 1995
II TABLE OF CONTENTS List of Tables List of Figures 1. INTRODUCTION Study Purpose Background 2. DEVELOPMENT OF ALTERNATIVES PAGE11 iii 1123 3. ROADWAYDESIGN 8 Affected Governmental Agencies
8 Affected Properties 9 Affected Utilities 9 Design Considerations 11 4. TRAFFIC OPERATION ANALYSIS 13 Procedure 13 I On-Site Data Collection 14 Calibration 14 Results 14 Traffic Operation
Analysis Conclusions 18 5. ENGINEER'S OPINION OF PROBABLE COST 20 6. RECOMMENDATIONS 23 Ii
1-I LIST OF TABLES PAGE Existing Conditions Measure of Effectiveness 16 II. 2 Alternative 1, Island Modifications Only Measure of Effectiveness 17 3 Alternative 3, SPill Measure of Effectiveness
18 4 Alternative 1, Island Modifications Only Cost Estimate 20 5 Alternative 2, Single Point Left Turns Cost Estimate 21 II 6 Alternative 3, SPill Cost Estimate 22 I r il 11
I 1234 Alternative 1 Alternative 2 Alternative 3 Turning Movement Counts LIST OF FIGURES III PAGE567 15
Ii 1. INTRODUCTION The Town of Addison is located within one of the fastest growing areas in Texas. Already recognized as a leading business, retail, and commercial center, the Town
continues to experience significant growth in retail, restaurant, and commercial development. The Town is also attracting new residential communities that could double its population
over the next decade. Increased traffic volumes have accompanied the growth in Addison and the surrounding area. The primary transportation network serving the Town and its local access
requirements must also serve the regional travel needs of the area. These sometimes conflicting functions coupled with the increasing traffic volumes have increased traffic congestion
along the Town's primary arterials. The Town's leaders placed a high priority on the effective and efficient movement oftraffic within and through the Town. The Town continually assesses
travel and safety conditions on its roadway system and implements improvements to facilitate improved traffic conditions. The Town continues to improve conditions at intersections throughout
the Town with the implementation of capacity improvements at the critical intersections along Belt Line Road. At the heart of the transportation system serving Addison is the intersection
of The Dallas North Tollway (DNT) and Belt Line Road. Belt Line Road is a major regional arterial thoroughfare serving North Dallas County. The Dallas North Tollway is a controlled access
toll facility serving travel between downtown Dallas and northern Dallas and southern Collin Counties. Major ingress and egress ramps to the DNT at Belt Line characterize the importance
of the interaction between these two major traffic carriers. STUDY PURPOSE The purpose ofthe study was to identify and evaluate alternatives for improving traffic conditions at the Dallas
North Tollway/Belt Line Road intersection and based on the results of the evaluations develop a preferred alternative for implementation. The criteria used for evaluation includes Level
of Service improvement, auto emissions reduction, and construction cost. 1
II il_IIc. I.I BACKGROUND Although technically within the city limits ofthe City ofDallas, the intersection, nonetheless, serves as the gateway to Addison from the north and south and
is the critical intersection for east/west travel within the Town. Increasing levels of congestion at this intersection during the peak hours now negatively impact traffic operation
at nearby intersections. Because of its importance to the overall transportation system in the area, congestion at this intersection impacts the effectiveness of the entire transportation
system Realizing the importance ofthis intersection to transportation in Addison, the Town Council retained Barton-Aschman Associates, Inc. to develop and analyze alternatives for improving
traffic conditions at this intersection. 2
2. DEVELOPMENT OF ALTERNATIVES Alternatives for evaluation were developed based on comments received from the Town ofAddison and field investigations. The alternatives were developed
using the following criteria: • Elevated roadway sections should not be considered. • Access to adjacent properties should be maintained. • No existing movements should be eliminated.
• Alternatives should consider relatively low-cost traffic system management improvements as well as major (high cost) improvements to the intersection. • Innovative alternatives should
be considered. Using these criteria, conceptual alternatives were developed and reviewed with Town of Addison staff. These conceptual alternatives included the following: ••• ii. i ••
TSM improvements to provide dual left-tum lanes from the DNT Frontage roads. Depressing the DNT frontage roads to allow through movements on the frontage roads to avoid the traffic signals
at the intersection. Depressing the DNT frontage roads and reconfiguring the left-tum lanes from from the frontage roads to allow concurrent let turns. Reconfiguring the left lanes on
the frontage roads to allow concurrent left-turns (no grade separation on frontage roads). Reconfigure the intersection to create a Single Point Urban Interchange (SPUr) . The SPUI is
a new form ofsignalized urban interchange that can provide significant added capacity over conventional diamond urban interchanges. The SPUI is particularly well-suited for restricted
right-of-way environments. The SPill is relatively new and, to date, there are none operating in the Dallas/Ft. Worth Area. A preliminary evaluation ofeach ofthese conceptual alternatives
was conducted to determine which alternatives should be considered for detailed analysis. The results ofthis evaluation were reviewed with Town staff. Based on this review ofthe conceptual
alternatives, depressing the frontage roads 3
l[Il . i!r' Ii to provide grade-separation for the frontage road through movements was eliminated for the following reasons: • Extensive relocation of utilities. • A preliminary profile
of the grade separation indicates that the terminus points ofthe vertical curves necessary to achieve the required clearance under Belt Line Road would negatively impact the operation
of the ingress and egress ramps to and from the Tollway. • The grade separation would negatively impact access to adjacent properties. • Cost. The remaining three alternatives are discussed
below and illustrated in Figures 1 thru 3. Alternative 1 Alternative 1 is a relatively low cost Transportation System management (TSM) approach to improving traffic conditions at the
intersection. Currently, both the northbound and southbound frontage roads have five approach lanes; one U-turn, one shared left and through lane, two through lanes, and one exclusive
right turn lane. This alternative would modify the intersection to allow leftturns from the U-turn lane, providing two lanes to service the high volumes of left-turns at the intersection.
This alternative requires no new right-of-way and only minor modifications to the intersection. Alternative 1 is illustrated in Figure 1. Alternative 2 Alternative 2 reconfigures the
frontage roads to provide a U-turn lane, dual left-turn lanes, three through lanes, and an exclusive right for both the northbound and southbound frontage roads. In addition, the left-turn
lanes are realigned to allow concurrent left-turns from the frontage roads. This provides the opportunity for more efficient traffic signal operation. The approaches on Belt Line Road
remain unchanged in this alternative. This alternative requires additional right-of-way along the frontage roads, and modifications to the existing bridge. Alternative 2 is illustrated
in Figure 2. Alternative 3 Alternative 3 creates a full single point urban intersection. In addition to the improvements presented in Alternative 2, the approaches on Belt Line Road
are reconfigured to provide exclusive dual left-turn lanes (aligned to run concurrently), three through lanes, and an exclusive right-tum lane on both the eastbound and westbound approaches.
This alternative requires additional right-ofway along the north side ofBelt Line Roads and a reduction in the width ofthe median on Belt Line. Alternative 3 is presented in Figure 3.
4
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FIGURE 3 BUILDING -:------EX. ROT DALLAS NORTH TOLLWAY ALTERNATIVE 3 RET. TALL RET. TALL 􀁾 IIII II 1l0BILI i (1111 II . 1,1 J I 1111 ::-----􀁟􀁾􀁾 􀁾 􀀼􀁾􀂷􀁉􀂷􀁉􀂷􀁬􀁪􀂷􀁉􀀢 II 􀁜􀁾
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II 3. ROADWAY DESIGN There are many factors to consider in the roadway design for any modifications to the Belt Line RoadlDallas Parkway intersection. Jurisdictional interests, right-of-way
needs, the effect on existing utilities, and drainage considerations are among the factors to be investigated and addressed. AFFECTED GOVERNMENTAL AGENCIES Modifications to the Belt
Line RoadlDallas Parkway intersection and the Belt Line Road Bridge over Dallas North Tollway will involve multiple jurisdictions and will probably require the execution of inter-local
agreements between the jurisdictions. The jurisdictions are represented by their respective engineering or public works department or agencies. The affected governmental agencies are
as follows: II II • Texas Turnpike Authority -The Texas Turnpike Authority is the owner/operator of the Dallas North Tollway. Modifications to the Belt Line Bridge should be coordinated
with the Turnpike Authority. The Turnpike Authority is located at: 3015 Raleigh Street Dallas, Texas 75219 (214) 522-6200 Town ofAddison -A portion ofBelt Line Road west ofDallas North
Tollway lies within the corporate limits of the Town of Addison. Street construction and modifications are administered through the Public Works Department located at: 16801 Westgrove
Drive Addison, Texas 75001 (214) 450-2886 8
r . II • City ofDallas -Belt Line Road over Dallas North Tollway and east ofthe Tollway lie within the City of Dallas. The Public Works and Transportation Department exercises control
over street construction while Dallas Water Utilities is responsible for water and wastewater facilities. These two agencies are each located at: 320 E. Jefferson Boulevard Dallas, Texas
75203 (214) 670-4245 (Public Works) (214) 948-4592 (Water Utilities) Dallas County -Although not directly involved, Dallas County, through its Public Works Department, may have an interest
in any proposed modifications at Belt Line and Dallas Parkway. Dallas Area Rapid Transit -DART may have an interest in the operational aspects of any proposed modifications at Belt Line
and Dallas Parkway. AFFECTED PROPERTIES Northeast Corner -Prestonwood Tower lies within the City of Dallas. Belt Line Road and Dallas Parkway at this corner lie within the City of Dallas.
Southeast Corner -Bed, Bath & Beyond (formerly Sakowitz) lies within the Town ofAddison along with northbound Dallas Parkway. Belt Line Road at this corner lies within the City of Dallas.
Southwest Corner -Mobil Self-Serve is located in the Town of Addison. Belt Line Road and southbound Dallas Parkway are situated in the Town of Addison also. Northwest Corner -Spectrum
Center lies within the Town of Addison along with westbound Belt Line Road. Southbound Dallas Parkway at this corner is located in the City of Dallas. AFFECTED UTILITIES The existing
utilities and facilities located at or adjacent to the Belt LinelDallas Parkway intersection are: -Water mains -Sanitary sewers -TU Electric -Lone Star Gas -Southwestern Bell Telephone
-Storm drainage Traffic signals -Median irrigation 9
• Water mains are located along Belt Line Road (however, not in the area of the bridge structure) and along Dallas Parkway. The depth of these mains in their current locations should
provide adequate cover after any pavement widening. Facilities related to the water mains such as fire hydrants, water valves, water vaults, water meters and water valve manholes will
require adjustments or relocation to accommodate pavement widening. Dallas Water Utilities and Town ofAddison facilities are involved. Sanitary sewer facilities will involve adjustments
to manholes and cleanouts but should not require any main reconstruction. Dallas Water Utilities and Town of Addison facilities are involved. TV Electric has overhead lines on wooden
poles along the north side ofBelt Line Road. The proposed pavement widening will require relocation of these facilities and these can be termed routine. A line of steel transmission
towers runs along the west side of northbound Dallas Parkway. In Alternatives 2 and 3 one tower conflicts with the proposed U-turn for northbound Dallas Parkway. Relocation ofthis tower
will require significant effort, time and money. TU Electric has four street lights in the Belt Line Road median that will be affected by the pavement widening. It is assumed that TU
Electric's franchise agreements with the Town ofAddison and the City of Dallas require relocations without cost to the Town or City. • Lone Star Gas has facilities along Belt Line Road
west of Dallas Parkway that may be affected by the proposed pavement widening. The existing depth is not known, but there should be no significant problems. Southwestern Bell Telephone
has extensive underground facilities along Belt Line Road. The depth ofthese facilities is not known, but it is assumed that the depth provides sufficient cover to allow pavement widening
without extensive relocations. Storm drainage mains belonging to the Town of Addison and the City of Dallas are located under existing street pavement. The proposed pavement widening
will not affect the existing drainage patterns, will not significantly increase run off, and will only require relocation of existing storm drain inlets. iII I!. •• Traffic signals at
the Belt Line/Dallas Parkway intersection are owned and operated by the City of Dallas. The proposed intersection modifications will require a complete redesign of the signal layout
and operation at this intersection. Median irrigation systems currently exist in the medians in both the City of Dallas and the Town of Addison. These facilities will be completely removed
and reconstructed as part of the pavement widening. 10
. DESIGN CONSIDERATIONS Design considerations for this project will include: -Belt Line Road Bridge -Pavement widening -Additional right-of-way -Existing driveways -Traffic control during
construction II I! • • The proposed left-tum and U-turn movements will require modifications to the Belt Line Road Bridge. These modifications involve additional structural analysis
and relocation or adjustment of attached lighted roadway signs for Dallas North Tollway. The existing clearance ofthe Belt Line bridge for northbound Dallas North Tollway is signed as
15'-7" while the southbound is signed as 17'-0". The proposed structural modifications will decrease the clearance by approximately 4" in each direction. Pavement widening is proposed
along the east side ofnorthbound Dallas Parkway north and south of Belt Line Road, along the west side of southbound Dallas Parkway north of Belt Line Road, along the north side ofBelt
Line Road east and west ofDallas Parkway and along the median in Belt Line Road east and west of Dallas Parkway. The south curb line of Belt Line is proposed to remain unchanged. The
majority of the existing pavement on Dallas Parkway and Belt Line Road will remain in place. Curbs will be removed in selected areas and new pavement will be added using steel dowels.
The transverse and longitudinal slopes ofthe proposed pavement widening will match the existing. Additional right-of-way will not be needed along the south side of Belt Line Road (Mobil
Self-Serve and Bed, Bath & Beyond frontage). Along the east side ofDallas Parkway south of Belt Line Road (Bed, Bath & Beyond), additional right-of-way with a maximum width of II-feet
will be needed to accommodate the pavement widening. The estimated additional right-of-way is approximately 3500 square feet and approximately 31 parking spaces may be eliminated. It
appears that additional right-of-way will be needed along the Belt Line Road and Dallas Parkway frontages of Spectrum Center. The Belt Line frontage will require an additional 8feet
while the Dallas Parkway frontage will require an additional II-feet. The estimated additional right-of-way is approximately 6500 square feet with no resulting loss of parking. Prestonwood
Tower will have a relatively small right-of-way impact. Right-of-way needed for the proposed widening consists of a comer clip and slivers of new right-of-way along 11
rI" •• Dallas Parkway and Belt Line Road. The estimated additional right-of-way at this corner is approximately 1000 square feet with a resulting displacement of about 10 parking spaces.
There are four existing driveways that will be directly affected by the proposed pavement widening. There is no proposed construction at the southwest corner ofBelt Line and Dallas Parkway
that will affect driveways. The same is true for the southeast corner. Spectrum Center has two driveways on Belt Line Road and none on Dallas Parkway that will be affected by the proposed
pavement widening. The same is true for Prestonwood Tower at the northeast corner of Belt Line and Dallas Parkway. Traffic control during construction will be handled in a similar manner
to recent and proposed construction along Belt Line Road in the Town ofAddison. The existing lane configuration will be maintained during construction in which the outside lane pavement
widening will occur first. Upon completion of the outside lane pavement, traffic will will be shifted to the north and then construction around the median will take place. At the conclusion
of construction activities, median irrigation and landscaping will take place. 12
iI t-!I! 4. TRAFFIC OPERATIONS ANALYSIS The Belt Line Road and Dallas Tollway frontage roads were simulated using TRAF-NETSIM, a microscopic street network simulation model. TRAF-NETSIM
was developed for the U.S. Department of Transportation, Federal Highway Administrative (FHWA), and has been nationally accepted for traffic operations analysis. The model accumulates
statistics on a vehicle by vehicle basis for stopped delay, total delay, average delay, average queue, maximum queue, fuel consumption, and vehicle emission rates. TRAF-NETSIM simulates
the movements of individual vehicles over one second time increments using probablistic techniques to randomize the simulation. The "drivers" are subject to car-following theory, lane-change
rules and gap acceptance rules taken from a random population with random characteristics. TRAF-NETSIM was used to provide a common reference for evaluating proposed alternatives with
existing conditions. PROCEDURE The following steps were completed for TRAF-NETSIM analysis: analysis: I. 1. 2. A field study of the site was made to determine the physical and operational
aspects of the existing conditions. Data collection efforts included: l-I:' l •••• PM peak hour turning movement counts were performed on Friday, March 23, 1995 from 4:00 PM to 6:00
PM. Existing timing plans were provided by the City of Dallas and verified in the field. A vehicle delay study was performed on Friday, March 24, 1995 from 4:00 PM to 6:00 PM. The Texas
Turnpike Authority provided "As Built" plans of the study location. 13
II· Ir: II,.IIi l. • Lane configurations were verified in the field. 3. Existing conditions using TRAF-NETSIM were modeled and calibrated. 4. Meeting were held with the Town of Addison
representatives to discuss the proposed alternatives. It was determined Alternatives 1 and 3 would be modeled using TRAFNETSIM. 5. Measure of Effectiveness were determined for each alternative.
6. Results and conclusions were documented. ON-SITE DATA COLLECTION Data collection consisted of turning movement counts and a stopped-delay study at Belt Line Road and Dallas Tollway
frontage roads.' Data collection was performed on Friday, March 24, 1995 from 4:00 PM to 6:00 PM during the peak hour to represent worst case conditions. The turning movement counts
are shown in figure 4. Stopped-time delay is determined by measuring the number of cars stopped on each approach every 15 seconds. These IS-second "snapshots" provide a sample of the
number of cars that are stopped. By assuming that each stopped vehicle stays stopped for the full 15 seconds, each counted vehicle represents 15 vehicle-seconds of stopped delay. The
sum of all the vehicles counted in this way is the total stopped delay. The stopped-delay study was used to compare the results of simulation with actual field performance. CALIBRATION
The TRAF-NETSIM model was calibrated based on stopped delay and maximum queue per approach. Driver performance characteristics such as maximum acceleration and mean queue discharge headway
were varied from the respective default values to replicate observed conditions at the study location. The simulation model was considered calibrated once the stopped delay and maximum
queue were brought to within an acceptable range of the data collected. In general, the TRAF-NETSIM default values were found to be more sluggish than what was measured in the field
at the study location. RESULTS Stopped delay, total delay, maximum queue, and vehicle emissions for the different scenarios studied are reported below. The stopped delay is defined as
the average time that a vehicle is stopped with 14
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1,1 ----.,., , _------􀁾 I I : '90.1-,1 Il' .......--r-l v '" lit 'UlI aNn J,'lall i I iii ' , I I 􀁾􀁶􀂣 II: : : _-----------..""" ,1j r I I I =-􀁟􀀮􀀮􀁉􀀭􀂷􀁟􀂷􀁟􀂷􀀭􀁔􀁴􀂷􀁟􀂷􀀱􀁩􀁩􀁾􀁌􀀻􀁗􀂷􀁟􀂷�
�􀁔􀁾􀀺 __------= 􀀹􀁾􀀶􀁾 _ : : :n : : I I pt I 1 : : :II t;99 􀁾􀀺􀀭􀀫􀀭􀀭 c::i i iii 􀁾􀁪􀁬 '\ 1[7 .,-----, ' d, ,"'iV ,M I : :: 1 : !'. to!' ( 􀁾􀁾 s ! \ 􀁾 􀁾 r//ID 􀁾􀀮􀀮􀀭􀀭􀀡􀀧
II i ..--OJ, i 􀁾 I I I I I I I I iI j II nIlI 1Ii \ .\ \j \\\
"jIJ locked wheels at an approach, and average total delay is defined as the average difference between the total approach time of a vehicle and the free flow travel time on an approach.
The maximum queue is defined as the maximum queue that occurs during the simulation time. Existing Conditions Based on the TRAF-NETSIM analysis the results for existing conditions are
shown in Table 1. The existing phasing is the standard Texas Transportation Institute (TTl) phasing with a 120 second cycle. Table 1: Existing Conditions Measures of Effectiveness Belt
Line 144.86 F 190.60 F 87.36 125 Westbound Southbound 146.45 F 192.70 F 46.53 73 Frontage Northbound 70.30 F 92.50 F 111.26 98 Frontage OVERALL 84.56 F 111.27 F 365.10 361.00 Alternative
1 Based on the TRAF-NETSIM analysis, the results for Alternative 1, are shown in Table 2. Alternative 1 was analyzed using existing signal timing and phasing. 16
)III Table 2: Alternative 1, Island Modifications Only Measures of Effectiveness I " ) Belt Line Eastbound Belt Line Westbound Southbound Frontage Northbound Frontage 40.36 147.90 110.80
38.08 EFFD 53.10 194.60 145.90 50.10 EFFD 120.60 90.93 54.49 104.43 65 126 56 63 OVERALL Alternative 2 69.75 F 91.78 F 370.45 310.00 i! IjI! TRAF-NETSIM analysis was not performed for
Alternative 2. Alternative 2 creates single point left turns for the frontage roads movements but not Belt Line Road movements. This would allow the frontage roads to run the left-turns
concurrently; however Belt Line would have to remain as the existing phasing. This will improve traffic operations from Alternative 1, but the phasing alternatives would be limited possibly
confusing to drivers. Alternative 3 Based on the TRAF-NETSIM analysis, the results for Alternative 3 are shown in Table 3. The results are based on a cycle length equivalent to the existing
cycle length of 120 seconds, and a four phase sequence. Protective/Perrnissive left-tum signal operation cannot be used with single point interchanges. A longer clearance interval is
required for this design than traditionally used withm phasing. In the four phase sequence analyzed the left-tum movements proceed their adjacent through movements. Leading left-turns
were used for the analysis because this phasing is commonly used and familiar to drivers. However, lagging left-turns could be used. The advantage to lagging left-turns is that a smaller
clearance interval would be required and create a more efficient use of signal time. 17
Table 3: Alternative 3, SPUI Measures of Effectiveness TRAFFIC OPERATIONS ANALYSIS CONCLUSIONS Based upon the analysis performed in this study, Alternative 3 shows significant reductions
in stopped delay, total delay, carbon monoxide emissions, and maximum queue. Alternative I shows reductions in the overall measures of effectiveness. 1J JI Belt Line 24.59 C 32.36 C
Eastbound Belt Line 33.23 D 43.72 D Westbound Southbound 43.95 E 57.83 E Frontage Northbound 55.51 E 73.05 E Frontage OVERALL 38.63 D 50.83 D 99.77 50 74.20 51 69.00 38 94.05 84 337.02
223 , )I j1III Alternative 1, island modifications only, was analyzed using the existing phasing and timing so that an easy comparison could be made with existing conditions. This alternative
will increase the capacity ofthe frontage roads. The measures ofeffectiveness for stopped delay, average total delay, and maximum queue show an overall improvement in traffic operations
for the interchange. There is a very minimum increase on the measures ofeffectiveness on Belt Line reflected in the table. This increase is caused by TRAF-NETSIM modeling procedures.
Alternative 1 reduces stop delay and average total delay by 17.5% and overall maximum queue by 14% and increases carbon monoxide emissions by 1.5%. Alternative 3, SPUI, will produce
significant reductions in the measure of effectiveness for the overall operation of the interchange. This alternative is expected to significantly increase capacity from the existing
oversaturated conditions. The analysis was done based on the existing cycle length; however the phasing and timing was optimized. While it is recommended that the frontage roads use
the same cycle length and coordinate with adjacent intersections to provide progression along Belt Line, the increase in capacity this option provides will allow flexibility in the phasing
and cycle lengths. 18
I .. > 1Ii .J On Belt Line, adjacent intersections to the interchange, Montfort and Quorum Drive, are very close in proximity to the frontage roads. During field observations it was
observed that queues along Belt Line come very close to adjacent intersections. For short periods oftime, the flow of traffic through adjacent intersections was impeded by the queues
at the frontage roads. The single point intersection significantly reduces queue length along Belt Line Road. This reduction in queue length is expected to eliminate the chance of vehicles
queuing into adjacent intersections and impeding traffic operations under nonnal traffic conditions. The actual effect at Montfort and Quorum goes beyond the scope of this project. Alternative
3 reduces stop delay and average total delay by 54%, carbon monoxide emission rates by 7.6% and overall maximum queue by 38%. 19
J) J] jI11]JjI 5. ENGINEER'S OPINION OF PROBABLE COST The cost associated with the improvements in each alternative vary directly with the complexity of the alternative. The benefit
derived from each alternative also increases with the cost and complexity of a specific alternative. The following tables show the Engineer's Opinion of Probable Cost for each of the
three alternatives. Table 4: Alternative 1, Island Modifications Only Cost Estimate 􀁉􀁃􀁲􀁰􀁾 '.}i'· .'. • '<>i /:ii::. .. >t;j(iL;'!).{i 􀀨􀀧􀁩􀁾􀁕􀁁􀁎􀁔􀁩􀁔􀁙 􀀺􀀻􀁕􀁎􀁉􀁔􀀧􀀺􀁐􀁒􀁉􀁃􀁅􀁾􀀩􀀺
􀀧􀁩􀁔􀁯􀁴􀁁􀁅􀀧􀁾 IV I : I .1'1 ,i,.··'.·'·.·.'. :p, 1-;' ..:.' :< . .' 􀀺􀁾􀀺􀂷􀁾􀀺􀁍􀁩􀀻􀀺􀀻􀀬􀀺􀁾􀁲􀀺􀀺􀀺 􀀮􀁾􀀾􀀺􀀺􀀢􀁾􀀭􀀬􀀬 . 􀀺􀀬􀀬􀀧􀀬􀁾􀀮 , ':' ': -, -,.", ...', :-''--.:..
:.-':.-;-.-..•.,-\ I> .• :'.'. ·•·•··..·.·."c···;;), " .:)':>': i( ',,: 'AMOUNT" MOBILIZATION LS 1 $10,000.00 $10,000.00 REMOVE OLD CONC (CURB) LF 95 $4.00 $380.00 REMOVE OLD CONC (MED)
SY 425 $7.00 $2,975.00 REMOVE OLD CONC SY $4.00 $0.00 (SIDEWALK) REPLACE CONC PAV (8") SY 42.7 $108.00 $4,612.00 CONC. CURB & GUTTER LF 40 $3.00 $120.00 CONCMED SY 18 $27.00 $486.00
MARKING AND STRIPING LS 1 $10,000.00 $10,000.00 SIGNING MODIFICAnONS LS 1 $10,000.00 $10,000.00 TRAFFIC CONTROL LS 1 $10,000.00 $10,000.00 TRAFFIC SIGNAL LS 1 $25,000.00 $25,000.00 MODIFICATINS
SUBTOTAL $73,573.00 CONTINGENCY @15% $11,037.00 GRAND TOTAL $84610.00 20
II1I -jiI :1I Table 5: Alternative 2, Single Point Left-Turns Cost Estimate .... ··c.-:,.<·· '",.....,>.(.... .... ..•...... >... I·eL. QuANtITY ,",•.'..\":-:". : ..... . ..'" !:{ '.,
I I' .I' 􀀧􀁬􀁾􀁟􀁬􀀺􀁫 ". j.< : ......... UNiT 'UNITPRICE•.· ,. . ''fOTAL' /" 􀀧􀀭􀀭􀁾􀀧􀀲􀀰􀁌􀀵􀀾 ,:. .:.... :.:-...,. 1;.(· ""'. .,:: -',: .... '-:-. 􀀮􀀭􀀮􀁾􀀺􀀬􀀮􀀬􀀭􀀧􀀢 ..,-,-;.
-.􀀻􀀺􀀧􀀺􀁾􀀮􀀺 "i:,>i:i)<';,:;'" .<-'[' , ·.A.Mooo;", '. ", MOBILIZATION LS 1 $10,000.00 $10,000.00 REMOVE OLD CONC (CURB) LF 1,440 $4.00 $5,760.00 REMOVE OLD CONC (MED) SY 279.7 $7.00
$1,958.00 REMOVE OLD CONC (SIDEWALK) SY 511.1 $4.00 $2,044.00 REPLACE CONC PAV (8") SY 805.1 $40.00 $86,951.00 CONC.CURB LF 1,085 $3.00 $3,255.00 CONCMED SY 390.6 $27.00 $10,545.00 SIDEWALK
SY 511.1 $24.00 $12,267.00 BRIDGE MODIFICATIONS SF 5,000 $50.00 $250,000.00 MARKING AND STRIPING LS 1 $10,000.00 $10,000.00 SIGNING MODIFICATIONS LS 1 $10,000.00 $10,000.00 SUBTOTAL
$402,780.00 CONTINGENCY @15% $60,420.00 SUBTOTAL $463,200.00 R.O.W. 7000 SF @$30.00/SF $210,000.00 GRAND TOTAL $673200.00 21
-\ 􀁾􀁉 ··1 .. j . Ij ;,1III Table 6: Alternative 3, SPUI Cost Estimate , :. .X;i ...::..:.... .•.. " -􀀭􀀭􀀭􀀭􀀭􀀬􀀧􀀬􀀭􀀺􀀧􀁾 ': ·· .. x,. 'x .... "", ITEMDESCRIPTION"'···.·:· UNIT'"
􀁑􀁕􀁁􀁎􀁔􀁾􀀧􀀺􀁬􀀧􀁙􀀧 UNITPIYCE ...., ......>• •:••.•􀂷􀀮􀂷􀀮􀂷􀀮􀁬􀂧􀀧􀁦􀁾􀁩􀀡􀂷􀂷 •.'., 􀀺􀀭􀀿􀁪􀁟􀀺􀁾􀀮􀀺􀀭 -.:':',:".':.'-.' " ....: >.', . ,.•. . '.. .' 'J' i. AMOUNT",' MOBILIZAnON
LS 1 $10,000.00 $10,000.00 CLEAR & GRUB LS 1 $20,000.00 $20,000.00 REMOVE OLD CONC (CURB) LF 3,340 $4.00 $13,360.00 REMOVE OLD CONC (MED) SY 600 $7.00 $4,200.00 REMOVE OLD CONC SY 790
$4.00 $3,160.00 (SIDEWALK) REPLACE CONC PAV (8") SY 4,000 $40.00 $160,000.00 REMOVE & REPLACE INLETS EA 4 $4,000.00 $16,000.00 CONCCURB LF 3,950 $3.00 $11,850.00 BRICK PAVERS SY 800
$30.00 $24,000.00 CONCMED SY 900 $27.00 $24,300.00 FIRE HYDRANT RELOCATION EA 4 $600.00 $2,400.00 SIDEWALK SY 950 $24.00 $22,800.00 WATER VALVEIMETER EA 20 $150.00 $3,000.00 RELOCATION
BRIDGE MODIFICATIONS SF 7,000 $50.00 $350,000.00 MARKTI"l"G AND STRIPING LS 1 $10,000.00 $10,000.00 TRAFFIC CONTROL LS 1 $10,000.00 $10,000.00 SIGNING MODIFICATIONS LS 1 $10,000.00 $10,000.00
SIGNAL MODIFICAnONS LS 1 $100,000.00 $100,000.00 SUBTOTAL $795,070.00 CONTINGENCY @15% $119,230.00 SUBTOTAL $914,300.00 R.O.W. $330,000.00 11,000 SF @$30/SF l:R ANIl TOTAl 􀁾􀀱 244 7.00
00 22
I) 1I J IJ 6. RECOMMENDATIONS Based upon design considerations, construction costs and traffic analysis Alternative 3, a Single Point Urban Interchange (SPUI), is recommended for the
Belt Line Road and Dallas Parkway interchange. A SPill will create additional capacity that will provide flexibility to provide efficient traffic flow along Belt Line Road. This recommendation
is expected to reduce stop delay and average total delay by 54%, carbon monoxide emission rates by 7.6% and overall maximum queue by 38% from existing conditions. The design of a SPUI
will be "new" to most drivers and pedestrians in this area. Care should be given throughout the design process to insure safety to pedestrians and motorist. Basic signal phasing for
a SPUI is not conducive to pedestrians crossing the road. Pedestrian safety should be emphasized with crosswalks and stop bars and consideration should be given to an actuated pedestrian
phase or a pedestrian overpass. Enhanced traffic control devices, such as pavement markings to delineate lane lines, turning paths, stop bars, cross walks, lighting and traffic guidance
signs should be considered. With these safety issues in mind during the design process a single point interchange can be safe and efficient to the motorist and significantly improve
traffic conditions. 23
BARTCN-A5t:HMAN ASSCt:IATES. INt:. 5485 Belt line Road, Suite 199, Dallas, Texas, 75240, (214) 991-1900. (214) 490-9261 fax ]10] :1]] J1 1
-j . 1j1 :jj JJI J1 -]t DESIGN REPORT FOR BELT LINE ROADIDALLAS PARKWAY INTERCHANGE PREPARED FOR Town of Addison PREPARED BY Barton-Aschman Associates,Inc.
.,.,1 ' "". "","",'''''' ..􀁾􀁾􀀢􀀬􀁾..., .T''''·''''··' ,T' .,..􀀻􀀮􀀻􀁾􀀮􀀮􀀬􀀮 .,."."" ,"',. """ ......,.,'" ",.,,,'' 􀁾0::: oZ MElRlC SCALE: 1: 1000 SINGLE POINT URBAN INTERCHANGE
BELT LINE ROAD AT DALLAS PARKWAY PKWY 1 ADD lHRU LANES ON DAL P NO. REVISION II SPIKOWITZ VILLAGE \\ .----24 PARKING SPACES LOST t ADDITIONAL R.O.W. 17.4 M2 (187 S.F.) MOBIL MART § Ea.
E0-0 0 0 0 "' "' in ,-<0 I I § § Ea. 0 0 0 0 "' "' '" ;; ADDIllONAL R.O.W. ,-------i..:L 460 M2 (4950 S.F.) .:<::\ ...:..... AM /NOON /PM PEDESTRIAN COUNTS (lHURS. -OCT. 2, 1997) .5/28/3.
SPECTRUM CEN TER ................􀀬􀀺􀀺􀀧􀀺􀀺􀀻􀀺􀀻􀁾􀀮􀀻􀀢􀀺􀀢􀀻􀀧....""".,,,....,,,,,...,,,,,,.......,,........,,"'",,..,,''''''''''''' ....􀁾 . . ,....."".,"',. ,..,.
0«0 0::: Wz ::J I---l 193 r-h 􀁾 r--193 r--L (;Tl ......-< t--' 192 -f-192 '---,... -191 191 190 190 􀁾 􀁾 ......... ......... l-I-􀁾 I.J.... 189 l!) 189 tV(DRrHE. l1" 0 V IUJ P--OUNe
􀁾 c:: CD cri ---....--0 I---. (::, /.,. .-.-188 r---'tR ... '-" 188 --f. f.--ROF"h 􀁾 ;0; ::::i!: ::::i!: 􀁾 􀁾􀁄 r-s-t 􀁾 .-l!) --------􀁾 187 􀁾 -c 0 en -187 􀁾JrHa --u--: tC l!)
l!) 􀁾V -e-􀁾)UND I---􀁾 ---= 186 ........ ......... CUll ',... r---186 􀁾 orr p 􀁾􀁏􀁆􀀢􀁉􀁌 r-<: 􀁾--::::--HO 􀁾􀁚 1: 100 􀁾 17 --A-" 185 􀁾 185 􀀭􀁾 L-. VEF T 1: 10 '-" 184 184 1+800
1+850 1+900 1+950 2+000 2+050 2+100 2+150 ,-SINGLE POINT URBAN INTERCHANGE BELT LINE ROAD AT DALLAS PARKWAY •AnY f§8N 1m ) 􀁰􀁾..􀁾􀀮􀁴􀀮􀁾􀁾􀁓􀁐􀁾􀁾􀁾􀀮􀁃􀁒􀁾􀁉􀁎􀁃􀁟 • 5485 􀁾􀀻􀁾􀁴􀀹􀁾􀀹􀀰􀀰􀁓􀁕􀁬
􀁮􀀺 􀁾􀀧􀁉􀁴 􀁾􀁁􀁘􀀺􀀰􀁾 􀀮􀁾􀀻􀀮􀀮􀀮􀀻􀁾 Designed: 􀁾􀀭􀀺􀀺􀀧 ...􀁾 l'IIIDUl."-""oc. ":1' Checked: Drown : 􀁾.. ""'" COIITIICII. sc-__T 􀀭􀁾 .. IICl. ...... NO. ........ 8Y CAll:
O1edced :
=t I C· BRIDGE RAIUNG .. 4 PARAPET WALL ... BRIDGE DECK EXTENSION EXISTING PAVEMENT E 0.9m 80 ... CANTILEVER BENT _L...--E􀁾 CANTILEVER BENT FACIA WALL ::i. :i 􀁾.,; 􀁾E O.9m DIA. DRILL
SHAFT 0 3.0 m (10.0') .,; I .V..I a: 􀁾 O.9m DIA. DRILL SHAFT I SHOULDER TRAVEL LANES I SINGLE POINT URBAN INTERCHANGE BELT LINE ROAD AT DALLAS PARKWAY 􀁾 ---ADDisoN 􀁾 PARSONS TRANSPORTATION
GROUP, INC. BARTON-A$OiIolAN . OeiLUW. CA.mER . smNWAN 5485 BELTUNE ROAD. SUI TE , 99 . DAU.AS. TEXAS 7521.0 (972) 991-1900 . FAX: (972) 490-9261 Designed: ....-STAT[ I 1UJ(JUIL MJ PROLeT
NO. "'tty DlV. NO. .... Checked: I Drown: srAIt """'TV I􀀢􀀢􀀺􀀭􀁉􀀵􀁅􀁾􀁾 I -;: HlCHW'" DlSf.NO. NO. NO. RE""SION BY OATE Checked: I I I .-
COST ESTIMATE ADDISON -SPUI :BELT LINE ROAD AND DALLAS NORTH TOLLWAY October 15, 1997 ITEM-NBR DESCRIPTION UNITS UNIT COST QUANTITY COST 100-5002 PREPR.O.W. KM $50,000.00 0.5 $25,000.00
104-5001 REMOV CONC (PAV) M2 $11.43 1000 $11,430.00 104-5005 REMOV CONC (MEDIAN) M2 $20.00 750 $15,000.00 104-5009 REMOV CONC (SDWLK) M2 $12.00 100 $1,200.00 104-5011 REMOV CONC (DRIVEWAY)
M2 $11.00, 200 $2,200.00 104-5013 REMOV CONC (CURB&GUTTER) M $4.72 1500 $7,080.00 260-5010 LIME TREAT SUBGR (DC) (200 MM) M2 $1.65 2500 $4,125.00 360-50 II CONC CURB (TY II) (MONO) M
$6.56 1500 $9,840.00 360-5017 CONC PAV (CPCD) (200MM) M2 $27.81 2000 $55,620.00 416-0506 DRILL SHAFT (36 IN) LF $77.49 400 $30,996.00 420-0551 CL C CONC (PARAPET WALL) CY $882.86 105
$92,700.30 420-5014 CL C CONC BENT M3 $395.00 150 $59,250.00 422-5001 REINF CONC SLAB M2 $71.79 1000 $71,790.00 423-5007 RET WALL M2 $375.00 200 $75,000.00 .450-0695 RAIL (TY C411) M
$209.98 200 $41,996.00 464-5005 RC PIPE (CL III) (600MM) M $124.32 30 $3,729.60 465-0741 INLET (COMPL) (TY II) (l0') EA $2,400.00 3 $7,200.00 496-0502 REMOVINLET EA $572.00 3 $1,716.00
5004-5001 TEMPSEDFNC M $1.00 2000 $2,000.00 5004-5003 TEMP SED FNC (REMOV) M $1.00 2000 $2,000.00 500-5001 MOBILIZATION LS $75,000.00 1 $75,000.00 502-5001 BARRICADE, SIGNS, TRAFF MO
$4,000.00 12 $48,000.00 530-5001 DRVWY'S (Conc)(l50mm) M2 $30.08 200 $6,016.00 531-5002 CONCRETE SIDEWALK M2 $19.27 150 $2,890.50 531-5004 SIDEWALK RAMP (TY 4) EA $463.00 16 $7,408.00
536-5002 CONCMEDIAN M2 $40.00 800 $32,000.00 610 RDWY ILL ASSEM EA $2,120.00 6 $12,720.00 649-5003 FND LG RDSD SIGN SUPPORT EA $292.35 20 $5,847.00 650 OVERHEAD SIGN SUPPORT EA $28,200.00
1 $28,200.00 662-0542 WZPM (CLB) EA $2.30 500 $1,150.00 662-0543 WZPM (CLB) EA $2.33 200 $466.00 662-0581 WZPM(TAB) EA $6.83 1500 $10,245.00 662-0582 WZPM (TAB) EA $1.00 750 $750.00
666-0517 REFL EA $99.48 24 $2,387.52
lTEM-NBR DESCRIPTION UNITS UNIT COST QUANTITY COST 666-0549 REFL EA $35.45 24 $850.80 666-5012 REFL M $12.50 75 $937.50 666-5013 REFL RA $89.02 24 $2,136.48 666-5036 REFL M $1.24 150
$186.00 666-5041 REFL M $2.50 250 $625.00 666-5044 REFL , M $8.63 75 $647.25 666-5045 REFL EA $36.32 24 $871.68 666-5201 REFL M $0.67 150 $100.50 666-5209 REFL M $7.76 250 $1,940.00
672-0504 RPM (CLA) EA $6.43 160 $1,028.80 672-0507 RPM (CLB) EA $2.43 360 $874.80 672-5016 RPMBTN EA $2.88 370 $1,065.60 678-5001 PAV SURV & PREP M $0.13 150 $19.50 678-5004 PAY SURV
& PREP M $2.72 250 $680.00 678-5006 PAY SURV & PREP M $5.73 75 $429.75 678-5007 PAY SURV & PREP EA $31.70 24 $760.80 678-5008 PAV SURV & PREP EA $40.00 24 $960.00 686 SIGNAL SYSTEM LS
$125,000.00 1 $125,000.00 LANDSCAPE LS $75,000.00 1 I $75,000.00 UTILRELOC LS $175,000.00 1 $175,000.00 SUBTOTAL $1,142,067.38 CONTINGENCY AND ENGINEERING $342,620.21 RIGHT-OF-WAY $540,000.00
TOTAL $2.024687.59·
HIGHWAY '0. STATE DlSl. NO. FED, ROAD STATE OIV. NO. ---ADDiSON METRIC SCALE: 1: 1000 SINGLE POINT URBAN INTERCHANGE BELT LINE ROAD AT DALLAS PARKWAY (-;a) p􀁁􀁾􀁾􀂣􀁾􀁾􀁈􀁍􀁉􀁾􀁁􀁾􀁓􀁾􀁾􀁾􀁊􀁾􀁁􀀱􀀡
􀁾􀁎 􀀮􀁇􀁒􀁱􀁾􀀧􀁾􀀧􀁁􀁎 INC. • 5485 BELT UNE ROAD, SUIT[ 199 • DALLAS, TEXAS 75240 (972) 991-1900 • FAX: (972) 490-9261 VIILLAGE o Designed : PKWY i Drawn : 1 ADD THRU LANES ON DAL
piG 1 98 Che,ked : NO. REV1SI0N 􀁂􀁾 OAT[ Checked: EXIST. R.O.W. \ '\ MOBIL MART 􀁜􀁾.. E E E 0 Q. 0. 8 0 0 0; '" '" ., «; I I E E E 0 0 0. 0 0 0 "0 '" '" ""' ADDI1l0NAL R.O.W. ---ll
460 M2 (4950 S.F.) AM /NOON /PM -' " PEDESTRIAN COUNTS (THURS. -OCT. 2, 1997) .5/28/3 SPECTRUM CENTER 􀁾􀁲􀀢􀀧􀀢 _'II',,, ..􀀬􀀬􀀮􀀬􀀮􀀬􀀮􀀬􀁾􀁾􀀮􀀧􀀺􀀮􀀧􀀮􀀻􀀮􀀺􀀺􀀺􀀻􀀺􀀻􀀻􀀻􀀬􀀬􀀮􀀬
••,••" ,.,.:...􀁾􀀮􀀮 ..' "" 0 • ..,
0«0(Y wZ ---l I----l 193 ,...., 􀁾 r--193 -L <.:rl I 􀁾rt--' 192 ,i r-----192 II -! -r--191 ! 191 I 190 i i 190 -;:: -;::1'-I ---. ---. III-􀁾 􀁾 􀁾 l.L.. 189 LO 189 􀁾DRrHf II a 􀁉􀁾
􀁉􀁬􀀮􀁬􀁾 OUNe 􀀮􀁾 C,to Ol .--0 􀁾 188 r-r.'I-,. .... 􀁉􀁾 ......... ---r---ItR f 188 r--ROFI g ::; 􀁉􀁾 􀁾 􀁾􀁾􀀩 -e-f 􀁾 10 LO .J-----187 I-.. Ol -187 􀁾􀁾􀁲􀁈􀀸􀀨 --tJ. t( ILO LO
􀁾t:-l.--€Y 􀁾DUND Gu.,.., --e-! ---= 186 r-. 􀀮􀁾 -r----186 􀁾 .1\ P ?OFIL 􀁾 17 r------V-HO RZ 1: 100 􀁾 185 ---A. I .-Pr' 185 􀁾f--17 VEF T 1: 10 <:;T 184 184 1+800 1+850 1+900 1+950
2+000 2+050 2+100 2+150 -. SINGLE POINT URBAN INTERCHANGE BELT LINE ROAD AT DALLAS PARKWAY -fl-AWfS8N lIDI􀁐􀁾􀀮􀀮􀁳􀀬􀂣􀀡􀁬􀁬􀀮􀀮􀁉􀀬􀀮􀁒􀁁􀁾􀁓􀁐􀁾􀀡􀁾􀀱􀁬􀀮􀁏􀁎 􀁾􀁱􀁵􀁾􀁉􀁎􀁃􀀮 •
􀀬􀀮􀁾 􀁾􀁾􀁾􀀢􀁾􀁾􀁓􀁕􀁉􀀱􀁛 􀁾􀁬􀁬􀁴 􀁾􀁵􀀺􀀰􀁾 􀀴􀁾􀁡􀁾􀁾 Designed: =-".. 'UOloll._"'llUI:C'l0G. 􀁾 ft. . Checlced : Oro." : n •• -􀁃􀁏􀁉􀁟􀀮􀁾 _.• ....-_.. HCl. ........ BY DAI"E
Check.ed :
=L [ C· BRIDGE RAIUNG .. • PARAPET WALL ... BRIDGE DECK EXTENSION EXISTING PAVEMENT E 0.9m E g.... CANTILEVER BENT -'---E 􀁾 CANTILEVER BENT II FACIA WALL ;i ..:..i. .,; -=E O.9m DIA.
DRILL SHAFT c 3.0 m (10.0') .,; I .I.I a: 􀁾 O.9m DIA. DRILL SHAFT SHOULDER TRAVEL LANES I SINGLE POINT URBAN INTERCHANGE BELT LINE ROAD AT DALLAS PARKWAY 􀁾 ---ADDisoN II 􀁾 PARSONS
TRANSPORTATION GROUP, INC. I BARTON-ASCHMAN . DelEUW. CATHER . STEIN"'AN 5485 BEl.TUNE ROAD. SUITE 199 . DAllAS. TEXAS 75240 (972) 991-1900 . FAX: (972) 490-9261 Designed: rED. ROAD
$TAl'[ I f'U:IDUIL AID MOLer NO. 􀁓􀁈􀁾􀀧 I l)V.No. Checked : I I Drown: stATE au,,", 􀁉􀀢􀀢􀀧􀀺􀀭􀁉􀀢􀁾􀀢􀀢􀀧􀁉 􀁾 HIGH..,:AY I OlST.NO. NO. RE\1S1ON BY OATE Checked: I I I I
COST ESTIMATE ADDISON -SPUI :BELT LINE ROAD AND DALLAS NORTH TOLLWAY October 15, 1997 ITEM-NBR DESCRIPTION UNITS UNIT COST QUANTITY COST 100-5002 PREPR.O.W. KM $50,000.00 0.5 $25,000.00
104-5001 REMOV CONC (PAY) M2 $11.43 1000 $11,430.00 104-5005 REMOV CONC (MEDIAN) M2 $20.00 750 $15,000.00 104-5009 REMOV CONC (SDWLK) M2 $12.00 100 $1,200.00 104-5011 REMOV CONC (DRIVEWAY)
M2 $11.00 200 $2,200.00 􀀱􀀰􀀴􀁾􀀵􀀰􀀱􀀳 REMOV CONC (CURB&GUTTER) M $4.72 1500 $7,080.00 260-5010 LIME TREAT SUBGR (DC) (200 MM) M2 $1.65 2500 $4,125.00 360-5011 CONC CURB (TY II) (MONO)
M $6.56 1500 $9,840.00 360-5017 CONC PAV (CPCD) (200MM) M2 $27.81 2000 $55,620.00 416-0506 DRILL SHAFT (36 IN) LF $77.49 400 $30,996.00 420-0551 CL C CONC (PARAPET WALL) CY $882.86 105
$92,700.30 420-5014 CL C CONC BENT M3 $395.00 150 $59,250.00 422-5001 REINF CONC SLAB M2 $71.79 1000 $71,790.00 423-5007 RET WALL M2 $375.00 200 $75,000.00 450-0695 RAIL (TY C411) M
$209.98 200 $41,996.00 464-5005 RC PIPE (CL III) (600MM) M $124.32 30 $3,729.60 465-0741 INLET (COMPL) (TY II) (10') EA $2,400.00 3 $7,200.00 496-0502 REMOV INLET EA $572.00 3 $1,716.00
5004-5001 TEMP SED FNC M $1.00 2000 $2,000.00 5004-5003 TEMP SED FNC (REMOV) M $1.00 2000 $2,000.00 500-5001 MOBILIZATION LS $75,000.00 1 $75,000.00 502-5001 BARRICADE, SIGNS, TRAH MO
$4,000.00 12 $48,000.00 530-5001 DRVWY'S (Conc)(150mm) M2 $30.08 200 $6,016.00 531-5002 CONCRETE SIDEWALK M2 $19.27 150 $2,890.50 531-5004 SIDEWALK RAMP (TY 4) EA $463.00 16 $7,408.00
536-5002 CONCMEDIAN M2 $40.00 800 $32,000.00 610 RDWY ILL ASSEM EA $2,120.00 6 $12,720.00 649-5003 FND LG RDSD SIGN SUPPORT EA $292.35 20 I $5,847.00 650 OVERHEAD SIGN SUPPORT EA $28,200.00
1 $28,200.00 662-0542 WZPM(CLB) EA $2.30 500 $1,150.00 662-0543 WZPM(CLB) EA $2.33 200 $466.00 662-0581 WZPM(TAB) EA $6.83 1500 $10,245.00 662-0582 WZPM(TAB) EA $1.00 750 $750.00 666-0517
REFL EA $99.48 24 $2,387.52
ITEM-NBR DESCRIPTION UNITS UNIT COST QUANTITY COST 666-0549 REFL EA $35.45 24 $850.80 666-5012 REFL M $12.50 75 $937.50 666-5013 REFL RA $89.02 24 $2,136.48 666-5036 REFL M $1.24 150
$186.00 666-5041 REFL M $2.50 250 $625.00 666-5044 REFL M $8.63 75 $647.25 666-5045 REFL EA $36.32 24 $871.68 666-5201 REFL M $0.67 150 $100.50 666-5209 REFL M $7.76 250 $1,940.00 672-0504
RPM (CLA) EA $6.43 160 $1,028.80 672-0507 RPM (CLB) EA $2.43 360 $874.80 672-5016 RPMBTN EA $2.88 370 $1,065.60 I 678-5001 PAY SURV & PREP M $0.13 150 II $19.50 678-5004 PAY SURV & PREP
M $2.72 250 I $680.00 678-5006 PAY SURV & PREP M $5.73 75 $429.75 678-5007 PAY SURV & PREP EA $31.70 24 $760.80 678-5008 PAV SURV & PREP EA $40.00 24 $960.00 686 SIGNAL SYSTEM LS $125,000.00
1 $125,000.00 LANDSCAPE LS $75,000.00 1 I $75,000.00 I UTILRELOC LS $175,000.00 I I $175,000.00 SUBTOTAL $1,142,067.38 CONTINGENCY AND ENGINEERING $342,620.21 RIGHT-OF-WAY $540,000.00
TOTAL $2,024,687.59·
I\ !JI .J DESIGN REPORT FOR BELT LINE ROADIDALLAS PARKWAY INTERCHANGE PREPARED FOR Town of Addison PREPARED BY Barton-Aschman Associates,Inc.
"j TABLE OF CONTENTS PAGE List of Tables 11 List ofFigures 111 1. INTRODUCTION 1 .\ Study Purpose 1 Background 2 )i . } 2. DEVELOPMENT OF ALTERNATIVES 3 3. ROADWAY DESIGN 8 Affected
Governmental Agencies 8 Affected Properties 9 Affected Utilities 9 Design Considerations 11 4. TRAFFIC OPERATION ANALYSIS 13 Procedure 13 On-Site Data Collection 14 Calibration 14 Results
14 i i Traffic Operation Analysis Conclusions 18 • i, 5. ENGINEER'S OPINION OF PROBABLE COST 20 6. RECOMMENDATIONS 23
12345 ! . ! 6 III .J LIST OF TABLES Existing Conditions Measure of Effectiveness Alternative 1, Island Modifications Only Measure of Effectiveness Alternative 3, SPUI Measure of Effectiveness
Alternative 1, Island Modifications Only Cost Estimate Alternative 2, Single Point Left Turns Cost Estimate Alternative 3, SPUI Cost Estimate 11 PAGE 16 17 18 20 21 22
I .. ' ',,!,. 􀁾􀀮 ;:; 1 LIST OF FIGURES 1 PAGE 1 Alternative 1 5 2 Alternative 2 6 I 3 Alternative 3 7 ), 4 Turning Movement Counts 15 ii i . J III
I -I))iI .. J 1. INTRODUCTION The Town of Addison is located within one of the fastest growing areas in Texas. Already recognized as a leading business, retail, and commercial center,
the Town continues to experience significant growth in retail, restaurant, and commercial development. The Town is also attracting new residential communities that could double its population
over the next decade. Increased traffic volumes have accompanied the growth in Addison and the surrounding area. The primary transportation network serving the Town and its local access
requirements must also serve the regional travel needs of the area. These sometimes conflicting functions coupled with the increasing traffic volumes have increased traffic congestion
along the Town's primary arterials. The Town's leaders placed a high priority on the effective and efficient movement of traffic within and through the Town. The Town continually assesses
travel and safety conditions on its roadway system and implements improvements to facilitate improved traffic conditions. The Town continues to improve conditions at intersections throughout
the Town with the implementation of capacity improvements at the critical intersections along Belt Line Road. At the heart of the transportation system serving Addison is the intersection
of The Dallas North Tollway (DNT) and Belt Line Road. Belt Line Road is a major regional arterial thoroughfare serving North Dallas County. The Dallas North Tollway is a controlled access
toll facility serving travel between downtown Dallas and northern Dallas and southern Collin Counties. Major ingress and egress ramps to the DNT at Belt Line characterize the importance
of the interaction between these two major traffic carriers. STUDY PURPOSE The purpose ofthe study was to identify and evaluate alternatives for improving traffic conditions at the Dallas
North TollwaylBelt Line Road intersection and based on the results of the evaluations develop a preferred alternative for implementation. The criteria used for evaluation evaluation
includes Level of Service improvement, auto emissions reduction, and construction cost. 1
,1'II , ! BACKGROUND Although technically within the city limits ofthe City ofDallas, the intersection, nonetheless, serves as the gateway to Addison from the north and south and is
the critical intersection for east/west travel within the Town. Increasing levels of congestion at this intersection during the peak hours now negatively impact traffic operation at
nearby intersections. Because of its importance to the overall transportation system in the area, congestion at this intersection impacts the effectiveness of the entire transportation
system Realizing the importance ofthis intersection to transportation in Addison, the Town Council retained Barton-Aschman Associates, Inc. to develop and analyze alternatives for improving
traffic conditions at this intersection. 2
I))I) 2. DEVELOPMENT OF ALTERNATIVES Alternatives for evaluation were developed based on comments received from the Town ofAddison and field investigations. The alternatives were developed
using the following criteria: IJ •••• • Elevated roadway sections should not be considered. Access to adjacent properties should be maintained. No existing movements should be eliminated.
Alternatives should consider relatively low-cost traffic system management improvements as well as major (high cost) improvements to the intersection. Innovative alternatives should
be considered. II I . jI) Using these criteria, conceptual alternatives were developed and reviewed with Town of Addison staff. These conceptual alternatives included the following:
• TSM improvements to provide dual left-turn lanes from the DNT Frontage roads. • Depressing the DNT frontage roads to allow through movements on the frontage roads to avoid the traffic
signals at the intersection. • Depressing the DNT frontage roads and reconfiguring the left-turn lanes from the frontage roads to allow concurrent let turns. • Reconfiguring the left
lanes on the frontage roads to allow concurrent left-turns (no grade separation on frontage roads). • Reconfigure the intersection to create a Single Point Urban Interchange (SPill)
. The SPUI is a new form ofsignalized urban interchange that can provide significant added capacity over conventional diamond urban interchanges. The SPUI is particularly well-suited
for restricted right-of-way environments. The SPill is relatively new and, to date, there are none operating in the DallaslFt. Worth Area. A preliminary evaluation ofeach ofthese conceptual
alternatives was conducted to determine which alternatives should be considered for detailed analysis. The results ofthis evaluation were reviewed with Town staff. Based on this review
ofthe conceptual alternatives, depressing the frontage roads 3
.1 to provide grade-separation for the frontage road through movements was eliminated for the following reasons: • Extensive relocation of utilities. • A preliminary profile of the grade
separation indicates that the terminus points of the vertical curves necessary to achieve the required clearance under Belt Line Road would negatively impact the operation of the ingress
and egress ramps to and from the Tollway. • The grade separation would negatively impact access to adjacent properties. • Cost. The remaining three alternatives are discussed below and
illustrated in Figures I thru 3. Alternative 1 Alternative 1 is a relatively low cost Transportation System management (TSM) approach to improving traffic conditions at the intersection.
Currently, both the northbound and southbound frontage roads have five approach lanes; one V-turn, one shared left and through lane, two through lanes, and one exclusive right turn lane.
This alternative would modify the intersection to allow leftturns from the V-turn lane, providing two lanes to service the high volumes of left-turns at the intersection. This alternative
requires no new right-of-way and only minor modifications to the intersection. Alternative 1 is illustrated in Figure 1. Alternative 2 Alternative 2 reconfigures the frontage roads to
provide a V-turn lane, dual left-turn lanes, three through lanes, and an exclusive right for both the northbound and southbound frontage roads. In addition, the left-turn lanes are realigned
to allow concurrent left-turns from the frontage roads. This provides the opportunity for more efficient traffic signal operation. The approaches on Belt Line Road remain unchanged in
this alternative. This alternative requires additional right-of-way along the frontage roads, and modifications to the existing bridge. Alternative 2 is illustrated in Figure 2. Alternative
3 Alternative 3 creates a full single point urban intersection. In addition to the improvements presented in Alternative 2, the approaches on Belt Line Road are reconfigured to provide
exclusive dual left-turn lanes (aligned to run concurrently), three through lanes, and an exclusive right-turn lane on both the eastbound and westbound approaches. This alternative requires
additional right-ofway along the north side of Belt Line Roads and a reduction in the width ofthe median on Belt Line. Alternative 3 is presented in Figure 3. 4
I j' -._--, I ,: 'I I I : I I I !I IIII I : 11..-------. I I !'=------􀁾 ." OJ j -t I J ---􀁾 .---I I. -1 I I Ii v I II-I I 􀀮􀁾 􀁉􀁾 I¥ I I § I I , 􀁾II I I; I , I 􀁾 ...... l.J. ....
+. I I I
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I I 􀁾 I (f) t 􀁾 I us 􀁾 ct Cl' 􀁾 􀁾 :j 1: 111 􀁾u. 0E-4 ::t= 􀁾􀁾 E-4 I \ 􀁾 • 􀁾 Ct') i 0Z CI 􀁾 ti I \ 2S 00 i 􀁾 􀁾 􀁾 I \ \ -< \ 􀁾 i 􀁾 􀁾 I 11 .J aNn .L11R \_-I-\ CO J (f =
Cr : \.\
IJ 3. ROADWAY DESIGN There are many factors to consider in the roadway design for any modifications to the Belt Line RoadJDallas Parkway intersection. Jurisdictional interests, right-of-way
needs, the effect on existing utilities, and drainage considerations are among the factors to be investigated and addressed. AFFECTED GOVERNMENTAL AGENCIES Modifications to the Belt
Line RoadJDallas Parkway intersection and the Belt Line Road Bridge over Dallas North Tollway will involve multiple jurisdictions and will probably require the execution of inter-local
agreements between the jurisdictions. The jurisdictions are represented by their respective engineering or public works department or agencies. The affected governmental agencies are
as follows: •• Texas Turnpike Authority -The Texas Turnpike Authority is the owner/operator of the Dallas North Tollway. Modifications to the Belt Line Bridge should be coordinated with
the Turnpike Authority. The Turnpike Authority is located at: 3015 Raleigh Street Dallas, Texas 75219 (214) 522-6200 Town ofAddison -A portion of Belt Line Road west of Dallas North
Tollway lies within the corporate limits of the Town of Addison. Street construction and modifications are administered through the Public Works Department located at: 16801 Westgrove
Drive Addison, Texas 75001 (214) 450-2886 8
]j . II ••• City ofDallas -Belt Line Road over Dallas North Tollway and east ofthe Tollway lie within the City of Dallas. The Public Works and Transportation Department exercises control
over street construction while Dallas Water Utilities is responsible for water and wastewater facilities. These two agencies are each located at: 320 E. Jefferson Boulevard Dallas, Texas
75203 (214) 670-4245 (public Works) (214) 948-4592 (Water Utilities) Dallas County -Although not directly involved, Dallas County, through its Public Works Department, may have an interest
in any proposed modifications at Belt Line and Dallas Parkway. Dallas Area Rapid Transit -DART may have an interest in the operational aspects of any proposed modifications at Belt Line
and Dallas Parkway. II AFFECTED PROPERTY OWNERS Northeast Corner -Prestonwood Tower lies within the City of Dallas. Belt Line Road and Dallas Parkway at this corner lie within the City
ofDallas. Southeast Corner -Bed, Bath & Beyond ( formerly Sakowitz) lies within the Town Town ofAddison along with northbound Dallas Parkway. Belt Line Road at this corner lies within
the City ofDallas. Southwest Corner -Mobil Self-Serve is located in the Town of Addison. Belt Line Road and southbound Dallas Parkway are situated in the Town of Addison also. Northwest
Corner -Spectrum Center lies within the Town ofAddison along with westbound Belt Line Road. Southbound Dallas Parkway at this corner is located in the City of Dallas. AFFECTED UTILITIES
The existing utilities and facilities located at or adjacent to the Belt LinelDallas Parkway intersection are: -Water mains -Sanitary sewers -TU Electric -Lone Star Gas -Southwestern
Bell Telephone -Storm drainage -Traffic signals -Median irrigation 9
ID Water mains are located along Belt Line Road (however, not in the area of the bridge structure) and along Dallas Parkway. The depth of these mains in their current locations should
provide adequate cover after any pavement widening. Facilities related to the water mains such as fire hydrants, water valves, water vaults, water meters and water valve manholes will
require adjustments or relocation to accommodate pavement widening. Dallas Water Utilities and Town of Addison facilities are involved. Sanitarv sewer facilities will involve adjustments
to manholes and cleanouts but should not require any main reconstruction. Dallas Water Utilities and Town of Addison facilities are involved. I .'I .1 "e TU Electric has overhead lines
on wooden poles along the north side of Belt Line Road. The proposed pavement widening will require relocation of these facilities and these can be termed routine. A line of steel transmission
towers runs along the west side of northbound Dallas Parkway. In Alternatives 2 and 3 one one tower conflicts with the proposed U-turn for northbound Dallas Parkway. Relocation ofthis
tower will require significant effort, time and money. TU Electric has four street lights in the Belt Line Road median that will be affected by the pavement widening. It is assumed that
TUElectric's franchise agreements with the Town ofAddison and the City ofDallas require relocations without cost to the Town or City. Lone Star Gas has facilities along Belt Line Road
west of Dallas Parkway that may be affected by the proposed pavement widening. The existing depth is not known, but there should be no significant problems. Southwestern Bell Telephone
has extensive underground facilities along Belt Line Road. The depth of these facilities is not known, but it is assumed that the depth provides sufficient cover to allow pavement widening
without extensive relocations. Storm drainage mains belonging to the Town of Addison and the City of Dallas are located under existing street pavement. The proposed pavement widening
will not affect the existing drainage patterns, will not significantly increase run off, and will only require relocation of existing storm drain inlets. e Traffic signals at the Belt
LineIDallas Parkway intersection are owned and operated by the City ofDallas. The proposed intersection modifications will require a complete redesign of the signal layout and operation
at this intersection. Median irrigation systems currently exist in the medians in both the City of Dallas and the Town ofAddison. These facilities will be completely removed and reconstructed
as part of the pavement widening. 10
'-DESIGN CONSIDERATIONS Design considerations for this project will include: -Belt Line Road Bridge -Pavement widening -Additional right-of-way -Existing driveways -Traffic control during
construction • The proposed left-turn and U-turn movements will require modifications to the Belt Line Road Bridge. These modifications involve additional structural analysis and relocation
or adjustment ofattached lighted roadway signs for Dallas North Tollway. Tne existing clearance ofthe Belt Line bridge for northbound Dallas North Tollway is signed as 15'-7" while the
southbound is signed as 17'-0". The proposed structural modifications will decrease the clearance by approximately 4" in each direction. • Pavement widening is proposed along the east
side ofnorthbound Dallas Parkway north and south of Belt Line Road, along the west side of southbound Dallas Parkway north of Belt Line Road, along the north side ofBelt Line Road east
and west ofDallas Parkway and along the median in Belt Line Road east and west of Dallas Parkway. The south curb line of Belt Line is proposed to remain unchanged. The majority of the
existing pavement on Dallas Parkway and Belt Line Road will remain in place. Curbs will be removed in selected areas and new pavement will be added using steel dowels. The transverse
and longitudinal slopes ofthe proposed pavement widening will match the existing. iII .1.1 • Additional right-of-way will not be needed along the south side ofBelt Line Road (Mobil Self-Serve
and Bed, Bath & Beyond frontage). Along the east side ofDallas Parkway south of Belt Line Road (Bed, Bath & Beyond), additional right-of-way with a maximum width of II-feet will be needed
to accommodate the pavement widening. The estimated additional right-of-way is approximately 3500 square feet and approximately 31 parking spaces may be eliminated. It appears that additional
right-of-way will be needed along the Belt Line Road and Dallas Parkway frontages of Spectrum Center. The Belt Line frontage will require an additional 8feet while the Dallas Dallas
Parkway frontage will require an additional ll-feet. The estimated additional right-of-way is approximately 6500 square feet with no resulting loss of parking. Prestonwood Tower will
have a relatively small right-of-way impact. Right-of-way needed for the proposed widening consists of a corner clip and slivers of new right-of-way along 11
Dallas Parkway and Belt Line Road. The estimated additional right-of-way at this comer is approximately 1000 square feet with a resulting displacement of about 10 parking spaces. • There
are four existing driveways that will be directly affected by the proposed pavement widening. There is no proposed construction at the southwest comer ofBelt Line and Dallas Parkway
that will affect driveways. The same is true for the southeast comer. Spectrum Center has two driveways on Belt Line Road and none on Dallas Parkway that will be affected by the proposed
pavement widening. The same is true for Prestonwood Tower at the northeast comer of Belt Line and Dallas Parkway. i JII • Traffic control during construction will be handled in a similar
manner to recent and proposed construction along Belt Line Road in the Town of Addison. The existing lane configuration will be maintained during construction in which the outside lane
pavement widening will occur first. Upon completion of the outside lane pavement, traffic will will be shifted to the north and then construction around the median will take place. At
the conclusion of construction activities, median irrigation and landscaping will take place. 12
) :j) .) . ! !IJ i j 4. TRAFFIC OPERATIONS ANALYSIS The Belt Line Road and Dallas Tollway frontage roads were simulated using TRAF-NETSIM, a microscopic street network simulation model.
TRAF-NETSIM was developed for the U.S. Department ofTransportation, Federal Highway Administrative (FHWA), and has been nationally accepted for traffic operations analysis. The model
accumulates statistics on a vehicle by vehicle basis for stopped delay, total delay, average delay, average queue, maximum queue, fuel consumption, and vehicle emission rates. TRAF-NETSIM
simulates the movements of individual vehicles over one second time increments using probablistic techniques to randomize the simulation. The "drivers" are subject to car-following theory,
lane-change rules and gap acceptance rules taken from a random population with random characteristics. TRAF-NETSIM was used to provide a common reference for evaluating proposed alternatives
with existing conditions. PROCEDURE The following steps were completed for TRAF-NETSIM analysis: 2. Data collection efforts included: I :1 1. A field study ofthe site was made to determine
the physical and operational aspects of the existing conditions. II • PM peak hour turning movement counts were performed on Friday, March 23, 1995 from 4:00 PM to 6:00 PM. • Existing
timing plans were provided by the City of Dallas and verified in the field. jII .1 •• A vehicle delay study was performed on Friday, March 24, 1995 from 4:00 PM to 6:00 PM. The Texas
Turnpike Authority provided "As Built" plans of the study location. 13
;CiJ !i .1 • Lane configurations were verified in the field. 3. Existing conditions using TRAF-NETSIM were modeled and calibrated. 4. Meeting were held with the Town of Addison representatives
to discuss the proposed alternatives. It was determined Alternatives 1 and 3 would be modeled using TRAFNETSIM. 5. Measure of Effectiveness were determined for each alternative. 6. Results
and conclusions were documented. ON-SITE DATA COLLECTION Data collection consisted ofturning movement counts and a stopped-delay study at Belt Line Road and Dallas Tollway frontage roads.
Data collection was performed on Friday, March 24, 1995 from 4:00 PM to 6:00 PM during the peak hour to represent worst case conditions. The turning movement counts are shown in figure
4. Stopped-time delay is determined by measuring the number ofcars stopped on each approach every 15 seconds. These IS-second "snapshots" provide a sample of the number of cars that
are stopped. By assuming that each stopped vehicle stays stopped for the full 15 seconds, each counted vehicle represents 15 vehicle-seconds of stopped delay. The sum of all the vehicles
counted in this way is the total stopped delay. The stopped-delay study was used to compare the results ofsimulation with actual field performance. CALIBRATION The TRAF-NETSIM model
was calibrated based on stopped delay and maximum queue per approach. Driver performance characteristics such as maximum acceleration and mean queue discharge headway were varied from
the respective default values to replicate observed conditions at the study location. The simulation model was considered calibrated once the stopped delay and maximum queue were brought
to within an acceptable range ofthe data collected. In general, the TRAF-NETSIM default values were found to be more sluggish than what was measured in the field at the study location.
RESULTS Stopped delay, total delay, maximum queue, and vehicle emissions for the different scenarios studied are reported below. The stopped delay is defined as the average time that
a vehicle is stopped with 14
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i 1 Hi i ! -9££ 􀁾 I I 􀁾􀁶􀂣 :,: : : =_-------....􀀭􀀮􀁬􀀭􀁊􀀮􀀭􀀭􀀭􀀭􀀭􀀭􀀴􀀱􀀭􀀭􀀭􀀮􀀭􀀭􀁭􀀭􀀮􀀭􀀭􀀭􀀱􀀭􀁢􀀭􀀭􀀭􀀭􀀭􀂷􀁻􀁾􀁾􀀭􀀭􀀭􀀭􀀭􀀭􀀭 􀀽􀀭 9 '6' : ' '" SLv K -\-\-_ :: III ::
I I III I t : : :Il c;99 􀁾􀀺􀀭􀀫􀀭 c::! i iii i h) 1f7 ... --------, ' ,j, ,1-J ,'A?\. I I 1,1 I I 􀁾􀁢􀀯􀀮 I ',' ' !'\ 1")1"-(g . I \ --<0 I. 􀁾 , ,1"'\ .q-0 rl lD 􀁾 --I"-II i .-co,
i U) I I I , I I I I II II, III􀁾IIII 1!,I \\
!I ), :,.-.:'!,iI I) locked wheels at an approach, and average total delay is defined as the average difference between the total approach time of a vehicle and the free flow travel
time on an approach. The maximum queue is defined as the maximum queue that occurs during the simulation time. Existing Conditions Based on the TRAP-NETSIM analysis the results for existing
conditions are shown in Table 1. The existing phasing is the standard Texas Transportation Institute (TTl) phasing with a 120 second cycle. Table 1: Existing Conditions Measures of Effectiveness
Belt Line 39.82 D 52.40 E 119.95 65 Eastbound Belt Line 144.86 F 190.60 F 87.36 125 Westbound Southbound 146.45 F 192.70 F 46.53 73 Frontage Northbound 70.30 F 92.50 F 111.26 98 Frontage
OVERALL 84.56 F 111.27 F 365.10 361.00 Alternative 1 Based on the TRAF-NETSIM analysis, the results for Alternative 1, are shown in Table 2. Alternative 1 was analyzed using existing
signal timing and phasing. 16
j1ij IJ[j Table 2: Alternative 1, Island Modifications Only Measures of Effectiveness Intersection Stopped Delay .Total Delay CO Max.. Avg. ....... LOS Avg. . LOS (kgIbr) QIle,ue' .;«.
• .. < ;"..'/>';"<" ···.Delay : " Delay 􀀭􀁾􀀺􀀮􀁜􀀻􀂻􀀺􀀭􀀮 􀀭􀁾􀁾􀀻􀁾􀀢􀀭 􀀢􀀬􀀭􀀭􀁾􀀮 . . .. .... ·,.,c •. 􀀮􀀻􀀮􀀻􀁦􀀻􀀮􀂷􀀺􀀻􀀧􀀬􀁾􀀼􀁾􀀼􀂷 ..,: Belt Line 40.36 E 53.10 E 120.60
65 Eastbound Belt Line 147.90 F 194.60 F 90.93 126 Westbound Southbound 110.80 F 145.90 F 54.49 56 Frontage Northbound 38.08 D 50.10 D 104.43 63 Frontage OVERALL 69.75 F 91.78 F 370.45
310.00 Alternative 2 TRAF-NETSIM analysis was not performed for Alternative 2. Alternative 2 creates single point left turns for the frontage roads movements but not Belt Line Road movements.
This would allow the frontage roads to run the left-turns concurrently; however Belt Line would have to remain as the existing phasing. This will improve traffic operations from Alternative
1, but the phasing alternatives would be limited possibly confusing to drivers. Alternative 3 Based on the TRAF-NETSIM analysis, the results for Alternative 3 are shown in Tabt'e 3.
The results are based on a cycle length equivalent to the existing cycle length of 120 seconds, and a four phase sequence. ProtectivefPermissive left-turn signal operation cannot be
used with single point interchanges. A longer clearance interval is required for this design than traditionally used with TIl phasing. In the four phase sequence analyzed the left-turn
movements proceed their adjacent through movements. Leading left-turns were used for the analysis because this phasing is commonly used and familiar to drivers. However, lagging left-turns
could be used. The advantage to lagging left-turns is that a smaller clearance interval would be required and create a more efficient use of signal time. 17
iITable 3: Alternative 3, SPUI Measures of Effectiveness Intersection Stopped Delay .. Avg. LOS Delay .Total Delay Avg. LOS Delay CO 􀂷􀁻􀁍􀁡􀁸􀁾 􀀨􀁫􀁧􀀯􀁢􀁲􀀩􀀹􀁴􀁩􀁥􀁴􀁩􀁾 Ii Belt
Line Eastbound Belt Line Westbound Southbound Frontage Northbound Frontage OVERALL 24.59 33.23 43.95 55.51 38.63 cDEED 32.36 43.72 57.83 73.05 50.83 cDEED 99.77 74.20 69.00 94.05 337.02
50 51 38 84 223 I IiI TRAFFIC OPERATIONS ANALYSIS CONCLUSIONS Based upon the analysis performed in this study, Alternative 3 shows significant reductions in stopped delay, total delay,
carbon monoxide emissions, and maximum queue. Alternative 1 shows reductions in the overall measures of effectiveness. Alternative 1, island modifications only, was analyzed using the
existing phasing and timing so that an easy comparison could be made with existing conditions. This alternative will increase the capacity ofthe frontage roads. The measures ofeffectiveness
for stopped delay, average total delay, and maximum queue show an overall improvement in traffic operations for the interchange. There is a very minimum increase on the measures ofeffectiveness
on Belt Line reflected in the table. 1bis increase is caused by TRAF-NETSIM modeling procedures. Alternative 1 reduces stop delay and average total delay by 17.5% and overall maximum
queue by 14% and increases carbon monoxide emissions by 1.5%. Alternative 3, SPUI, will produce significant reductions in the measure of effectiveness for the overall operation ofthe
interchange. This alternative is expected to significantly increase capacity from the existing oversaturated conditions. The analysis was done based on the existing cycle length; however
the phasing and timing was optimized. While it is recommended that the frontage roads use the same cycle length and coordinate with adjacent intersections to provide progression along
Belt Line, the increase in capacity this option provides will allow flexibility in the phasing and cycle lengths. 18
! . I On Belt Line, adjacent intersections to the interchange, Montfort and Quorum Drive, are very close in proximity to the frontage roads. During field observations it was observed
that queues along Belt Line come very close to adjacent intersections. For short periods oftime, the flow of traffic through adjacent intersections was impeded by the queues at the frontage
roads. The single point intersection significantly reduces queue length along Belt Line Road. This reduction in queue length is expected to eliminate the chance of vehicles queuing into
adjacent intersections and impeding traffic operations under normal traffic conditions. The actual effect at Montfort and Quorum goes beyond the scope ofthis project. Alternative 3 reduces
stop delay and average total delay by 54%, carbon monoxide emission rates by 7.6% and overall maximum queue by 38%. 19
1I .1.JIi . "] .-!! 5. ENGINEER'S OPINION OF PROBABLE COST The cost associated with the improvements in each alternative vary directly with the complexity of the alternative. The benefit
derived from each alternative also increases with the cost and complexity of a specific alternative. The following tables show the Engineer's Opinion of Probable Cost for each of the
three alternatives. Table 4: Alternative 1, Island Modifications Only Cost Estimate .'.......... ': .c·· ), .;>:" ..,.....,:.' ".'. ,.',.:....::.". .' . ,.,."" ITEM DESCRIPTION UNIT:'
'QUA:N,·r,·.;.T,:,i ITY ..U..N, IT. ::..p..R. ICE. :: TOTAL 1< AMOUNT MOBIUZATION LS 1 $10,000.00 $10,000.00 REMOVE OLD CONC (CURB) LF 95 $4.00 $380.00 REMOVE OLD CONC (MED) SY 425 $7.00
$2,975.00 REMOVE OLD CONC SY $4.00 $0.00 (SIDEWALK) REPLACE CONC PAV (8") SY 42.7 $108.00 $4,612.00 CONC. CURB & GUTTER LF 40 $3.00 $120.00 CONCMED SY 18 $27.00 $486.00 MARKING AND STRIPING
LS 1 $10,000.00 $10,000.00 SIGNING MODIFICAnONS LS 1 $10,000.00 $10,000.00 SUBTOTAL $38,573.00 CONTINGENCY @15% $5,786.00 GRAND TOTAL $44.358.00 20
iJ Table 5: Alternative 2, Single Point Left-Turns Cost Estimate .'. ....... ITEM DESCRIPTION ,UNIT·...., QUANTITY UNIT PRICE ..TOTAL ., .......;.. I: .......... '.; .' .. . . .; '>AMOuNr'
MOBIUlAnON LS 1 $10,000.00 $10,000.00 REMOVE OLD CONC (CURB) LF 1,440 $4.00 $5,760.00 REMOVE OLD CONC (MED) SY 279.7 $7.00 $1,958.00 REMOVE OLD CONC (SIDEWALK) SY 511.1 $4.00 $2,044.00
REPLACE CONC PAV (8") SY 805.1 $40.00 $86,951.00 CONC.CURB LF 1,085 $3.00 $3,255.00 CONCMED SY 390.6 $27.00 $10,545.00 SIDEWALK SY 511.1 $24.00 $12,267.00 BRIDGE MODIFICAnONS SF 5,000
$40.00 $200,000.00 MARKING AND STRIPING LS 1 $10,000.00 $10,000.00 SIGNING MODIFICAnONS LS 1 $10,000.00 $10,000.00 SUBTOTAL $352,780.00 CONTINGENCY@15% $52,917.00 GRAND TOTAL $405.697.00
21
,I] II) .I Table 6: Alternative 3, SPUI Cost Estimate ....... ITEM DESCRIPTION UNIT QUANTITY UNIT PRICE TOTAL . AMOUNT MOBIUZATION LS 1 $10,000.00 $10,000.00 CLEAR & GRUB LS 1 $20,000.00
$20,000.00 REMOVE OLD CONC (CURB) LF 3,340 $4.00 $13,360.00 REMOVE OLD CONC (MED) SY 600 $7.00 $4,200.00 REMOVE OLD CONC SY 790 $4.00 $3,160.00 (SIDEWALK) REPLACE CONC PAV (8") SY 4,000
$40.00 $160,000.00 REMOVE & REPLACE INLETS EA 4 $4,000.00 $16,000.00 CONCCURB LF 3,950 $3.00 $11,850.00 BRICK PAVERS SY 800 $30.00 $24,000.00 CONCMED SY 900 $27.00 $24,300.00 FIRE HYDRANT
RELOCAnON EA 4 $600.00 $2,400.00 SIDEWALK SY 950 $24.00 $22,800.00 WATER VALVEIMETER EA 20 $150.00 $3,000.00 RELOCATION BRIDGE MODIFICATIONS SF 7,000 $50.00 $350,000.00 MARKING AND STRIPING
LS 1 $10,000.00 $10,000.00 TRAFFIC CONTROL LS 1 $10,000.00 $10,000.00 SIGNING MODIFICAnONS LS 1 $10,000.00 $10,000.00 SIGNAL MODIFICAnONS LS 1 $100,000.00 $100,000.00 SUBTOTAL $795,070.00
CONTINGENCY @15% $119,230.00 SUBTOTAL $914,300.00 R.O.W. $330,000.00 11,000 SF @$30/30/SF 􀁾􀁒􀁁􀁎􀁮 TOTAl. 11:1 .,ALi 􀁾􀁮􀁮 nn 22
i j)I III 6. RECOMMENDATIONS Based upon design considerations, construction costs and traffic analysis Alternative 3, a Single Point Urban Interchange (SPUI), is recommended for the
Belt Line Road and Dallas Parkway interchange. The SPUI will provide the most cost effective solution to the congestion problem currently experienced. A SPUI will create additional capacity
that will provide flexibility to provide efficient traffic flow along Belt Line Road. This recommendation is expected to reduce stop delay and average total delay by 54%, carbon monoxide
emission rates by 7.6% and overall maximum queue by 38% from existing conditions. The design of a SPUI will be "new" to most drivers and pedestrians in this area. Care should be given
throughout the design process to insure safety to pedestrians and motorists. Basic signal phasing for a SPUI is not conducive to pedestrians crossing the road. Pedestrian safety should
be emphasized with crosswalks and stop bars and consideration should be given to an actuated pedestrian phase or a pedestrian overpass. Enhanced traffic control devices, such as pavement
markings to delineate lane lines, turning paths, stop bars, cross walks, lighting and traffic guidance signs should be considered. With these safety issues in mind during the design
process a single point interchange can be safe and efficient to the motorist and can significantly improve traffic conditions. 23