Evaluating Alternative Operations Strategies to Improve Travel Time ...

SHRP 2 L11: Final Appendices
A 1994 evaluation showed that the COMPASS Downsview TMC, built and operated by the Ministry of Transport, Ontario, has
resulted in a reduction in average duration of incidents from 86 minutes to 30 minutes. And the system prevented about 200
accidents per year (32).
The Wisconsin DOT’s freeway traffic management system resulted in a decrease in crashes of 14.8 percent (32).
A study of the INFORM system on Long Island, New York found a 15 percent accident reduction and a 9 percent increase in speed
(32).
• Mobility: A Freeway Management System in South Africa estimated by up to 48% reduction in travel times and up to 25% of
additional throughput. These remarkable results were due to the combined implementation Closed Circuit TV (CCTV) systems,
Dynamic Message Signs (DMS), in vehicle monitoring and toll collection (12).
The Michigan Intelligent Transportation System Center reduced delays from incidents by about 40 percent and increased the speed
by 8 percent (32).
The Wisconsin DOT’s freeway traffic management system reduced the travel time by 9, 12, and 16 percent on three separate
roadway segments. AM peak period average speed increased 3 percent while volume increased 22 percent. Net savings of 1,454
driver hours per peak hour were calculated as a result of ramp metering alone (32).
An estimate of average freeway incident time savings as a result of the Houston TranStar system is 5 minutes, and a savings of 30
minutes is possible for major freeway incidents. Total annual delay savings is estimated at 573,095 vehicle-hours (32).
Because of Atlanta’s NaviGAtor, the delay between the report of a crash and dispatch of emergency services has been cut in half,
and accidents are cleared from the roadway 38 percent faster (32).
• Efficiency: An evaluation of the effect of Wisconsin DOT’s highway TMC in the Milwaukee metropolitan area on highway
operations revealed 5:1 benefit-cost ratio excluding cost savings from crashes (41).
A statewide TOC-based freeway management program in Maryland yielded an overall benefit-cost ratio of 7:1 (41).
The Total annual delay savings at Houston TranStar, a multiagency TMC at Houston Texas, is estimated at 573,095 vehicle-hours,
resulting in about $8.4 million in savings per year (42).
• Energy/Environment: The Michigan Intelligent Transportation System Center lead to an annual reduction of 41.3 million gallons
of fuel used, a reduction of 122,000 tons of carbon monoxide, 1,400 tons of hydrocarbon and 1,200 tons of nitrogen oxides (42).
Signal Retiming/Optimization
• Safety: Signal retiming in Lexington, KY, USA, reduced stop and-go traffic delays by about 40 percent and accidents by 31
percent (39).
ADDITIONAL DESCRIPTION AND QUANTITATIVE BENEFITS OF TRAVEL-TIME RELIABILITY STRATEGIES Page F-35