Colorado DOT's comparison of two adaptive signal deployments.
Woodland Park, Colorado, United States
Greeley, Colorado, United States
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)*
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Study Period
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Corridor
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Fuel Consumption
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Pollutant Emissions
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Carbon Monoxide
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Hydro-Carbons
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Nitrogen Oxides
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Carbon Dioxide
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Overall Weekday
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10th Street
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3%
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4%
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9%
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4%
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3%
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US 24
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2%
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2%
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0%
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1%
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2%
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Overall Weekend
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10th Street
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4%
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4%
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13%
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5%
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4%
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US 24
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7%
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7%
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17%
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10%
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7%
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*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.