Features

SAN FRANCISCO – Many of the state’s regions have switched to public transportation powered by alternative fuels, but the San Francisco Bay area has opted to keep the noisier, dirtier diesel-burning buses. 

The state Air Resources Board had considered having large transit agencies stop buying diesel buses completely and have them use cleaner compressed or liquefied natural gas buses instead. Then it would have required the transit agencies to use buses powered by hydrogen fuel cells. 

Southern California air-quality officials as well as environmentalists pushed for the ban, but Bay Area transit operators lobbied to keep the option to buy diesel buses until 2015, which won out. 

Thirteen of the Bay Area’s 15 transit agencies are staying with diesel, but the Air Resources Board is considering eliminating the diesel option. It will vote in March on whether to require all agencies to buy only natural gas and other alternative fuel buses. 

Diesel exhaust, mostly from trucks and buses, is responsible for 70 percent of the cancer risk from air pollution, and nitrogen oxide from diesel trucks and buses is a prime ingredient in smog. 

Bay Area transit officials, however, say it’s not cost effective to convert to alternative-fuel buses, and then again to fuel cells. 

About 88 percent of the Bay Area bus fleet is diesel. Los Angeles’ fleet is 50 percent diesel, and Sacramento’s is 35 percent.