TR9302-SY 920501 FILE COPY
TRAFFIC LIGHT ~,l~v i~
SYNCHRONIZATION PROGRAM II
"BEFORE" STUDY RESULTS
FOR THE
COPPELL SIGNAL SYSTEM
(Contract 582TLF6043)
PREPARED FOR:
THE STATE DEPARTMENT OF HIGHWAYS
AND
PUBLIC TRANSPORTATION
SUBMITTED BY:
THE CITY OF COPPELL, TEXAS
PREPARED BY:
BARTON-ASCHMAN ASSOCIATES, INC.
Dallas, Texas
TRAFFIC LIGHT
SYNCHRONIZATION PROGRAM II
"BEFORE" STUDY RESULTS
FOR THE
COPPELL SIGNAL SYSTEM
(Contract 582TLF6043)
PREPARED FOR:
THE STATE DEPARTMENT OF HIGHWAYS
AND
PUBLIC TRANSPORTATION
SUBMITTED BY:
THE CITY OF COPPELL, TEXAS
PREPARED BY:
BARTON-ASCHIVIAN ASSOCIATES, INC.
Dallas, Texas
MAY, 1992
TABLE OF CONTENTS
PAGE
List of Tables ii
List of Figures iii
1. INTRODUCTION 1
Network Description 1
2. TRAFFIC DATA COLLECTION 4
Traffic Volumes 4
Signal Phasing and Timing 4
Intersection Geometrics 9
Travel Time Data 9
3. "BEFORE" STUDY ANALYSIS RESULTS 11
Calibration Study 1 1
TRANSYT-7F Results 1 2
Annual Operating Costs 15
LIST OF FIGURES
PAGE
I TLS Project Study Limits 2
2 Intersection Identification and Link Distances 3
3 AM Peak Hour (7:30 - 8:30 a.m.) Turning Movement Volumes 5
4 Noon/Off Peak Hour (1 2:00 - 1:00 p.m.) Turning Movement Volumes 6
5 PM Peak Hour (5:30 p.m. - 6:00 p.m.) Turning Movement Volumes 7
6 24-Hour Count Volumes 8
7 Existing Intersection Lane Configurations 10
o.o
Iii
LIST OF TABLES
PAGE
1 Existing Travel Time Summary 9
2 TRANSYT-7F Calibration Summary 1 2
3a Summary of Results for AM Peak Period 13
3b Summary of Results for Noon/Off Peak Period 1 3
3c Summary of Results for PM Peak Period 14
4 Coppell System Annual Cost Summary 16
ii
INTRODUCTION
The Traffic Light Synchronization Program II (TLS II) is a State grant program funded under
the Oil Overcharge Act and administered by the Texas Department of Transportation (TxDOT).
The program is designed to reduce vehicle fuel consumption, delay, and vehicle stops by
providing funding assistance to cities for the retiming and coordination of traffic signals.
Similar programs conducted nationwide has shown that one of the greatest benefits to the
public for each dollar spent on traffic operations comes from traffic signal timing and
coordination improvements.
This study evaluates and documents the "before" (existing) traffic signal operations for nine
(9) signalized intersections located in Coppell, Texas. The study boundaries are shown in
Figure 1.
Network Description
_ The study network is comprised of three (3) arterials within the City of Coppell, Texas. The
City of Coppell has a population of approximately 16,881 people and is a suburban
community in north Dallas County.
The traffic signal network in this project has nine (9) intersections. Two (2) signal
subsystems and one isolated location have been proposed for this project. The network
_ groupings are listed below along the with number of signals in each system:
· Belt Line Road - two (2) signals
· Denton Tap Road - six (6) signals
· MacArthur Blvd - one (1) signals
Total Intersections - 9
Figure 2 shows the location of each study intersection, link distances between intersections,
and intersection study node designations. All of the intersections, are isolated and run "free"
-- throughout the entire day.
1
Parkway Blvd.
Not to Scale
Sandy Lake Rd. Q //~ Q Sandy Lake Rd.
__-- Bethel School
2 oo'
Bethel ~it ti
FIGURE 2
_ INTERSECTION IDENTIFICATIONS
AND LINK DISTANCES
3
TRAFFIC DATA COLLECTION
As part of the "Before" Study, Barton-Aschman Associates, inc. collected peak hour turning
movement volumes, signal phasing and timing data, and network travel time data using the
floating car technique. All of this data was collected to evaluate and calibrate existing
conditions ("Before" conditions). TRANSYT-7F, a signal timing simulation/optimization
computer program, was utilized to evaluate the operating characteristics of the study
intersections.
Traffic Volumes
AM, Noon/Off, and PM peak hour turning movement traffic volumes were collected during the
month of March, 1992. The AM, Noon/Off, and PM-peak volumes are shown in Figures 3,
4, and 5, respectively. The AM peak period was found to occur between 7:30 a.m. and 8:30
a.m. The Noon/Off peak period occurred between 12:00 a.m. and 1:00 p.m. The PM peak
period occurred between 5:00 p.m. and 6:00 p.m. Twenty-four hour counts were conducted
to define the traffic patterns and daily traffic variations. Twenty-four hour counts for Denton
-- Tap Road are illustrated in Figure 6.
Signal Phasing and Timing
All nine (9) intersections of the system are fully actuated. Traffic demands dictate the phase
sequence and phase length at fully actuated intersections. Due to the nature of fully actuated
_ controllers, average phasing and timing was developed from field observations. If a particular
movement had no vehicular volume in a cycle then that phase would not receive green time
during the cycle. If the average (sum of field observations divided by the number of field
_ observations) phase length (green + yellow + all red) was two (2) seconds or less then this
phase was not included in the TRANSYT-7F runs. If the phase length was in the range of
three (3) to five (5) seconds, then this phase length was increased to a minimum of six (6)
second minimum phase duration. The average and/or actual phase sequence and phase length
are inputs to the "Before" condition in TRANSYT-7F runs.
-- 4
o
c~ ,-,- ~_25
/-274
141- co~.~-
I
Sandy Lake Rd. ~ --165 ~ ~k --243
~343 ~116 Sandy Lake Rd.
111 IO~ 228
~0~
63 · c
135TM ~o
~375
106~
39--
42 -~ ~=3
~ FIGURE 3
A.M. PEAK HOUR TRAFFIC VOLUMES
m~ed ~.20
Parkway Blvd. ~k
/- 58
36
o~ ~ Not to Scale
~202 ~60 Sandy Lake Rd.
60~
118~
~ ~126
.27 ~
~105
25
10-~ ~
~ FIGURE 4
NOON PEAK HOUR TRAFFIC VOLUMES
,
8
~ ~..87
Parkway Blvd. ~ ..,-30
,~-133
m m Not to Scale
~ ~85 ~1 ~ 55
Sandy Lake Rd. ~k ~140 ~ J[tl~273
~221 ~f~1~58 Sandy Lake Rd.
221~ 29
90~
m~ ~126
Bethel School ~ 86
30~ · c
97~
24--
Wranglar '~
,- FIGURE 5
P.M. PEAK HOUR TRAFFIC VOLUMES
- ·
Intersection Geometrics
Figure 7 depicts the intersection approach configurations and lane assignments for each of
the study intersections. The saturation flows used in the TRANSYT-7F modelling program
were derived from this diagram.
Travel Time Data
The network travel time information was gathered in the field using the floating car technique.
Travel time runs were conducted along Denton Tap for the AM, Noon/Off and PM peak
periods in both directions. A minimum of six (6) runs were conducted in each direction during
each peak period. The average AM, Noon/Off and PM peak, results from these travel time
studies are shown in Table 1. The travel time is given in seconds between the intersections.
The time was started at the beginning of the green phase for three (3) runs, and the beginning
of the red phase for three (3) runs. The running time is calculated as the travel time minus
the stop delay. The average run speed is calculated by dividing the section length by the
travel time.
TABLE 1
EXISTING TRAVEL TIME SUMMARY
AVERAGE TRAVEL TIME (SEC)
Southbound Northbound
Arterial Link AM Noon/Off PM AM Noon/Off PM
Denton Tap
-- Parkway 9.67 10.33 8.83 53.00 56.33 48.67
Sandy Lake 54.50 62.67 57.00 73.83 71.00 79.33
Bethel School 52.17 63.17 58.67 39.00 37.67 34.83
Bethel 38.83 43.67 41.67 48.50 44.00 46.83
-- Belt Line 50.33 44.00 52.83 54.67 48.50 54.17
Wrangler 54.50 49.00 49.33 11.67 2.83 2.67
TOTALS 260.00 272.84 268.33 280.67 260.33 266.50
-- 9
Not to Scale
FIGURE 7
-- EXISTING LANE CONFIGURATIONS
m
"BEFORE" STUDY ANALYSIS RESULTS
The purpose of the "Before" study is to quantify the existing conditions and to calibrate the
TRANSYT-7F model so that an accurate Before/After comparison can be made in the final
report.
Calibration Study
The existing AM, Noon/Off, and PM peak turning movement volumes, saturation flow rates,
as well as signal phasing and timing data were input into the TRANSYT-TF model to simulate
existing conditions. The saturation flow rates used for separate left turn lanes and for through
lanes were estimated to be 1,600 and 1,700 vehicles per hour, respectively. To calibrate, the
TRANSYT-7F (vehicle-hours/hour) was converted into a total TRANSYT-TF travel time
(seconds) and compared with the total travel times. The total TRANSYT-7F time is calculated
by multiplying the observed TRANSYT-TF (vehicle-hours/hour) time by 3,600 and divided by
the approach volume.
The percent difference between the observed and TRANSYT-7F travel times for the AM,
Noon/Off, and PM-peak comparisons are shown in Table 2. The goal was to calibrate the
-- computer model to replicate existing conditions to within a tolerance of twenty percent
(20%). The percent difference between the total travel times fell within the desired range for
all peak periods.
-- 11
TABLE 2
TRANSYT-7F CALIBRATION SUMMARY
Total Total %
Observed T7F Change
Travel Travel Between
Peak Time Time Observed
Arterial Direction Period (sec) (sec) and T7F
Denton Tap SB AM 260.00 302.80 -16.46
NB AM 280.67 267.26 4.78
Denton Tap SB Noon/Off 272.84 254.32 -6.79
NB Noon/Off 260.33 238.29 8.46
Denton Tap SB PM 268.33 271.66 1.24
NB PM 266.50 242.35 -9.06
TRANSYT-7F Results
The existing conditions at each intersection were analyzed with respect to fuel consumption,
total delay and the number of vehicle stops. The TRANSYT-7F results for the AM, Noon/Off,
and PM peak periods are summarized in Tables 3a, 3b, and 3c, respectively. This information
will be used to calculate annual operating costs for the study intersection.
-- 12
TABLE 3A
SUMMARY OF RESULTS
AM PEAK PERIOD
Fuel
Consumption Total Delay Uniform Stops
Intersection (Gal/Hr) (Veh-Hr/Hr) (Veh/Hr)
Denton Tap/Parkway 63.38 41.88 1,729.1
Denton Tap/Sandy Lake 102.48 47.1 2 2,009.8
Denton Tap/Bethel School 89.12 10.26 2,199.8
Denton Tap/Bethel 61.34 6.51 1,475.3
Denton Tap/Belt Line 97.15 13.61 2,240.8
Denton Tap/Wrangler 63.48 27.05 939.6
Belt Line/Moore 43.28 8.38 1,036.1
Belt Line/Mockingbird 238.67 259.48 819.9
MacArthur/Sandy Lake 159.84 188.15 1,616.5
TOTALS 918.74 602.44 14,066.9
TABLE 3B
SUMMARY OF RESULTS
NOON/OFF PEAK PERIOD
Fuel
Consumption Total Delay Uniform Stops
Intersection (Gal/Hr) (Veh-Hr/Hr) (Veh/Hr)
-- Denton Tap/Parkway 10.87 1.34 283.8
Denton Tap/Sandy Lake 46.58 7.98 1,278.7
Denton Tap/Bethel School 62.56 28.28 1,044.7
-- Denton Tap/Bethel 37.04 13.08 605.4
Denton Tap/Belt Line 42.94 2.86 800.8
Denton Tap/Wrangler 19.21 1.93 439.5
-- Belt Line/Moore 22.07 5.01 460.6
Belt Line/Mockingbird 5.12 1.34 326.2
MacArthur/Sandy Lake 16.41 7.27 797.3
TOTALS 262.80 69.09 6,037.0
_ 13
TABLE 3C
SUMMARY OF RESULTS
PM PEAK PERIOD
Fuel
Consumption Total Delay Uniform Stops
Intersection (Gal/Hr) (Veh-Hr/Hr) (Veh/Hr)
Denton Tap/Parkway 40.71 32.47 1,222.6
Denton Tap/Sandy Lake 74.79 13.73 2,039.4
Denton Tap/Bethel School 64.53 8.78 1,796.8
Denton Tap/Bethel 56.32 12.29 1,346.3
Denton Tap/Belt Line 148.41 85.15 2,067.0
Denton Tap/Wrangler 27.51 5.17 1,105.7
Belt Line/Moore 11.38 4.44 627.8
Belt Line/Mockingbird 12.41 2.98 736.7
MacArthur/Sandy Lake 49.43 37.02 1,672.8
TOTALS 485.49 202.03 12,615.1
-- 14
Annual Operating Costs
Table 4 summarizes the annual operating costs for the Coppell system. These operating costs
are based on TRANSYT-7F fuel consumption, total delay, and total stops outputs. The annual
operating costs were developed for each intersection. Fuel was assumed to cost $1.00 per
gallon; delay was assumed to be $10 per vehicle hour of delay; and stop costs were
calculated at $0.014 per stop.
The operating costs were annualized over 300 days. The AM and PM peal< periods were
determined to be 2 hours each and the Noon/Off peal< period was determined to be 8 hours
long. Therefore, the length of each day was assumed to be 12 hours. As shown in Table 4,
the annual operating costs for the entire system is approximately $8,355,216.00.
15
TABLE 4
COPPELL SYSTEM
ANNUAL COST SUMMARY
H°brlY Measures °f Effecfi~eness :
Fuel
Consumption Total Delay Uniform Stops
Peak Period (Gal/Hr) (Veh-Hr/Hr) (Veh/Hr)
AM Peak 918.74 602.44 14,066.9
Noon/Off Peak 262.80 69.09 6,037.0
PM Peak 485.49 202.03 12,615.10
Fuel
Consumption Total Delay Uniform Stops
Peak Period (S/Hr) (S/Hr) (S/Hr)
AM Peak $918.74 6,024.40 196.94
Noon/Off Peak 262.80 690.90 84.52
PM Peak 485.49 2,020.30 176.61
Annual Operating C°sts
Fuel
Consumption Total Delay Uniform Stops
Peak Period ($/Yr) ($/Yr) ($/Yr)
AM Peak $551,244.00 $3,614,640.00 $118,164.00
-- Noon/Off Peak 630,720.00 1,658,160.00 202,848.00
PM Peak 291,294.00 1,212,180.00 105,966.00
-- TOTAL ANNUAL COST $8,385,216.00
-- 16