Installation of adaptive signal control systems in two corridors in Colorado reduced fuel consumption by 2 to 7 percent and pollution emissions by up to 17 percent.

Colorado DOT's comparison of two adaptive signal deployments.

Date Posted
12/11/2012
Identifier
2012-B00808
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Adaptive Signal Timing Comparison between the InSync and QuicTrac Adaptive Signal Systems Installed in Colorado

Summary Information

The Colorado Department of Transportation (CDOT) implemented two separate adaptive signal control systems, one in Region 2 and another in Region 4. This study was done as a comparison between two different technologies deployed in two different environments. In Region 2, the City of Greeley, in conjunction with CDOT installed InSync adaptive signals at 11 10th Street (US 34 Business) intersections. In Region 4, QuicTrac adaptive signals were installed at 8 intersections along US 24 in Woodland Park. These upgrades were made to meet the goals of the FHWA "Every Day Counts" initiative.

Findings
Through reduction in travel times and the number of stops on both corridors, fuel consumption was estimated to have improved by 3 to 4 percent on the 10th Street corridor and 2 to 7 percent on the US 24 corridor based on a before-after comparison. Various types of pollutant emissions were estimated to have improved by 3 to 13 percent on the 10th Street corridor and 0 to 17 percent on the US 24 corridor. See Table 4 below for more detail.

Table 4. Fuel and Emissions Results

MOE Benefit (Percent Change)*
Study Period
Corridor
Fuel Consumption
Pollutant Emissions
Carbon Monoxide
Hydro-Carbons
Nitrogen Oxides
Carbon Dioxide
Overall Weekday
10th Street
3%
4%
9%
4%
3%
US 24
2%
2%
0%
1%
2%
Overall Weekend
10th Street
4%
4%
13%
5%
4%
US 24
7%
7%
17%
10%
7%

*Percentage change is computed by comparing the after study MOE to the before study MOE. A positive percentage change represents an improvement in that MOE.