Reducing the speed limits on San Francisco Bay Area highways from 65 to 55 is an idea being considered by the Metropolitan Transportation Commission, the regional intra-governmental body tasked with helping the Bay Area comply with a state law requiring air pollution reductions of 15% by the year 2035.
Dropping the maximum limit by 10 mph could reduce emissions 6% by 2035 — the equivalent of taking 300,000 cars off the road, Amir Fanai of the Bay Area Air Quality Management District, told the San Francisco Examiner.
Research shows vehicles are most environmentally efficient when they travel between 40 and 55 mph, Fanai said. Accelerating by just 10 mph — from 55 to 65 — can double emissions.
“A good portion of the Bay Area travel is on the freeway, and a good portion of that is spent moving over 55 mph,” Fanai said. “If we could reduce the speed limit by 10 mph, it would have a major impact on our air quality.”
The air quality effort is part of Plan Bay Area, an extensive carbon-reduction program overseen by the Metropolitan Transportation Commission and the Association of Bay Area Governments, two regional groups tasked with reducing the area’s greenhouse gases by7% by 2020 and 15% by 2035. Other measures also are being considered to meet those mandates.
For the next year, Plan Bay Area will be discussed with various communities. A vote on the initiative is scheduled for 2013.