Synchronizing traffic lights on Alicia Parkway, a major corridor in California, reduced the number of stops by 75 percent and lowered greenhouse gas emissions by 7 percent.
Mobility and environmental benefits realized from the Traffic Light Synchronization Program implemented in Orange County, CA.
The TLSP aimed to reduce the number of stops on the corridor, thereby improving mobility. Implementation included upgrades to traffic management systems, intersection traffic signal controllers, communication systems, and new optimized signal timing. The synchronization system, which is typically activated during the morning and evening peak traffic hours, uses timers that are set to congestion levels to turn traffic lights green.
To determine the impact of synchronizing traffic lights on the Alicia corridor, before and after studies used data obtained from traffic in the westbound and eastbound directions in the morning, midday, and evening periods. The studies compared travel times (in minutes), the number of stops, average speed, and greenhouse gas production across the different conditions.
The implementation produced a system that used timers set to current traffic patterns and congestion levels to turn traffic lights green, resulting in a reduction in travel delay and lower vehicle emissions. Specifically, the project produced the following benefits:
- Average commute speed increased by as much as 31 percent.
- An overall reduction of up to 75 percent in the number of stops.
- An 11 percent reduction in travel times.
- A savings of 1.1 million gallons of fuel over three years.
- A reduction of 7 percent reduction in greenhouse gas emissions.
The findings suggest that inter-jurisdictional cooperation in signal synchronization projects will produce greater benefits compared to when jurisdictions act independently from one another.
Published By: ITS International
Source Date: May 25, 2011URL: http://www.itsinternational.com/features/article.cfm?recordID=4643
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