Benefit

Coordinated signal timing on the arterial network in Syracuse, New York reduced vehicular delay by 14 to 19 percent, decreased total stops by 11 to 16 percent, and increased average speed by 7 to 17 percent.

Coordinated Signal Timing on a Arterial in Syracuse, NY


September 2003
Syracuse; New York; United States


Summary Information

In response to Onondaga County not meeting air quality standards in 1993, the City of Syracuse implemented the Signal Interconnect Design Project. The project standardized 145 intersections within the City of Syracuse and optimized the signal timing in an attempt to reduce automobile emissions by creating a more efficient network.

The study area included 37 of the 145 intersections, all located along five main arterials. The analysis involved comparison of simulation results representing conditions before and after implementation of the coordinated signal timing. The Synchro™ software package was used to model the performance of the system before and after the improvement project. The before data were collected in 1998 and consist of traffic counts for three time periods (AM, Mid-day, PM), as well as signal timing data. Field travel time data was collected, both before and after implementation, to confirm that the times estimated by the simulations accurately represented actual travel times.

The network simulation was run multiple times to optimize the signal timing. Once the optimized configuration was determined, the signal timings were implemented into the field controllers. To account for real-world conditions not accurately represented in Synchro™, staff calculated field adjustments to the traffic signal timing plans by driving the arterials multiple times at all time periods. These final adjustments, implemented in early 2000, were then input into the Synchro™ package, the simulation tool was run for the thirty-seven intersections, and the performance measures were calculated.

Traffic counts used in the simulation model for both the before and after case were collected in 1998. The authors felt that the 1998 data accurately represented after conditions due to little to no development or population changes in the study area.

FINDINGS

Results of the simulations representing before (1998) and after (2000) conditions are summarized below.

Measure of Effectiveness
Unit of Measure
AM PEAK PERIOD
MID DAY PEAK PERIOD
PM PEAK PERIOD
Before
After
Before
After
Before
After
Signal Delayseconds/veh
14
12
13
11
16
13
Total Stopseach
26,411
23,467
19,840
16,734
30,003
25,236
Average Vehicle Speedmiles/hour
14
15
13
15
12
14
Measure of Effectiveness
Unit of Measure
Range of Improvement
(by intersection)
Range of Improvement
(entire network)
Total Vehicular Delayseconds/veh
7.14%
80.95%
14.29%
18.75%
Total Stopseach
-3.84%
84.81%
11.15%
15.89%
Average Vehicle Speedmiles/hour
0.00%
66.67%
7.14%
16.67%

The study observed improvements in most system performance measures for the entire network over all three time periods. When analyzing each intersection individually, a large range of improvement is observed and, in some cases, there is no improvement or decline. The upper and lower bounds on the ranges of improvement measured by intersection were varied by time period for all metrics. Notably, when observing the ranges of improvement for the entire network, the lower bound for all metrics is found exclusively in the AM time period and the upper bound for all metrics is found exclusively in the PM time period.

Improvements in travel time on each of the five main arterials ranged from 1.15 to 34.20 percent during the AM peak, -2.71 to 35.10 percent during the Mid Day period, and -13.88 to 31.18 percent during the PM peak. Level of Service (calculated by seconds of delay) was calculated for 41 intersections, at three different times of the day, for a total of 123 measures. Thirty-six of these measurements improved, 73 remained the same and 14 declined.

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Source

Syracuse Signal Interconnect Project: Before and After Analysis Final Report

Author: DMJM Harris

Correspondence with NYSDOT, 2004

Correspondence with DMJM Harris

Published By: New York State DOT

Prepared by DMJM Harris for the New York State DOT

Source Date: September 2003


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Goal Areas

Mobility

Typical Deployment Locations

Metropolitan Areas

Keywords

coordinated signals, signal coordination, centralized signal control, signal synchronization, traffic signals, advanced signal control, signal timing optimization, coordinated signal control, advanced signal controller, traffic signal retiming, retiming, pre-timed, pretimed, time-of-day signal timing, fixed-time

Benefit ID: 2007-00398