Evaluating Alternative Operations Strategies to Improve Travel Time ...

SHRP 2 L11: Final Appendices
122 standard four-leg intersections on Long Island were studied for signal retiming in New York, Eight percent fewer reportable
crashes were recorded during the 36 months relative to the control sites. Crashes involving pedestrians and bicyclists dropped 37
percent relative to the control group of intersections. The researchers found a 12 percent reduction in injury crashes. The
experimental sites were 9 percent less likely than the controls to report multiple vehicle injury crashes (40).
• Mobility: The Texas Traffic Light Synchronization Program reduced delay by 23 percent by updating traffic signal control
equipment and optimizing signal timing on a previously coordinated arterial. Travel Time lowered by 14% (1).
Traffic signal retiming programs resulted in travel time and delay reductions of 5 to 20 percent, and fuel savings of 10 to 15 percent
across the nation (2).
Traffic Signal retiming at 11 intersections on U.S. Route 1 in St. Augustine, Florida reduced delay by 36% and travel time by 10%
(3).
Burlington, Canada had travel time lowered by 7 percent after retiming 62 intersections (3).
• Efficiency: Benefit-to-cost ratios for traffic signal optimization range from 17:1 to 175:1 (1).
On San Jose Boulevard in Jacksonville, FL, retiming traffic signals at a 25-intersection section reduced average arterial delay by 35
percent, arterial stops by 39 percent and arterial travel time by 7 percent, resulting in estimated annual fuel savings of 65,000
gallons and overall annual cost savings of $2.5 million (2001 (39).
On U.S. 1 in St. Augustine, FL,USA, retiming traffic signals at a 11-intersection arterial reduced average arterial delay by 36
percent, arterial stops by 49 percent and arterial travel time by 10 percent, resulting in estimated annual fuel savings of 26,000
gallons and overall annual cost savings of $1.1 million (2001) (39).
• Energy/Environment: Signal retiming projects were found to reduce fuel consumption by 2 to 9% in several U.S. and Canadian
cities (1).
Traffic Signal Preemption at Grade Crossings
• Safety: Automated enforcement systems have reduced highway-rail crossing violations by 78 to 92 percent along two corridors in
Los Angeles, California (1).
In Baltimore, a ""second train coming"" warning system decreased the frequency of the most common risky behavior at crossings
(i.e., drivers that crossed the tracks after the protection gates began to ascend from the first train before the protection gates could
be redeployed for the second train) by 26 percent (1).
• Mobility: In San Antonio, a modeling study found that if traffic congestion were to increase by 25 percent, posting nearby railroad
crossing closing delays on freeway dynamic message signs would reduce total network delay by up to 6.7 percent (1).
ADDITIONAL DESCRIPTION AND QUANTITATIVE BENEFITS OF TRAVEL-TIME RELIABILITY STRATEGIES Page F-36