In general, public transit agencies have increased spending on transit services since the mid-1980s. This has been due primarily to the cost of compliance with two significant federal laws passed in the early 1990s: the Clean Air Act and the Americans with Disabilities Act (ADA). To comply, transit agencies had to begin to purchase new cleaner fuel buses and retrofit buses with wheelchair lifts, rather than spending new funds on operations. At the same time, in the mid-1990s, the federal government slowly eliminated transit operating assistance funds, a major source of operating assistance for many of California's transit agencies. The two federal mandates combined with federal budget cuts to public transit coincide with a loss of ridership among all transit agencies in California in the mid-1990s.

Despite this dip, ridership on the state's 200 largest public transit systems has grown by nearly ten percent overall since 1985. Yet, this aggregate number masks large individual fluctuations among the hundreds of transit systems across the state. Some transit agencies have lost passengers. Those that have lost the most tend to be those that have either raised fares or reduced service. AC Transit in Alameda and Contra Costa counties lost 32 percent of its ridership since 1982 in the wake of several rounds of service cutbacks, including a round of massive night and weekend service cuts in the wake of federal budget cuts in the mid-1990s. The Los Angeles County MTA bus system has lost 13 percent of its ridership since 1990, after it raised fares from $.50 a ride to $1.35.

On the other end of the scale, there are agencies experiencing major increases. Since 1982, the Orange County Transit District has seen a 90 percent increase in bus passengers, San Diego Transit has had an 87 percent increase in its bus patronage, and the San Francisco Peninsula's Caltrain has experienced a 66 percent increase in commuter rail ridership.