As part of the Congestion Mitigation and Air Quality Improvement Program (CMAQ), the San Francisco freeway service patrol has been in operation since August 1992. As of January 1997, the program has assisted more than 90,000 drivers. It has decreased air pollution and reduced fuel consumption by helping to reduce the effects of incident caused congestion, start-and-stop travel and vehicle idling. Estimates indicate a reduction in 32 kg/day of hydrocarbons, 322 kg/day of CO emissions, and NOx is reduced by 798 kg/day.
As a result of reducing incident detection and response time, the TranStar Management Center helps to reduce hydrocarbons by 91 kg/day.