SAN FRANCISCO — California, known for its far-ranging suburbs and jam-packed traffic, is close to adopting a law intended to slow the increase in emissions of heat-trapping gases by encouraging housing close to job sites, rail lines and bus stops to shorten the time people spend in their cars.

The measure, which the state Assembly passed on Monday and awaits final approval by the Senate, would be the nation's most comprehensive effort to reduce sprawl. It would loosely tie tens of billions of dollars in state and federal transportation subsidies to cities' and counties' compliance with efforts to slow the inexorable increase in driving. The goal is to encourage housing near current development and to reduce commutes to work.

Gov. Arnold Schwarzenegger, a Republican, has not said whether he will sign the bill.

The number of miles driven in California has increased at a rate 50 percent faster than the rate of population growth for the past two decades. Passenger vehicles, which produce about 30 percent of the state's heat-trapping gases, are the single greatest source of such emissions.

The fragile coalition behind the measure includes some longtime antagonists, in particular homebuilders and leading environmental groups in California. Both called the measure historic.

"What California is doing for the first time," said Ed Manning, a lobbyist who represents the state's 25 largest homebuilding companies, "is planning for housing needs, transportation needs and climate-change needs all at the same time."

Thomas Adams, the board president of California's League of Conservation Voters, said the changes were "all going to support a development pattern that will help the state meet its climate goals."

The bill yokes three regulatory and permit processes. One focuses on regional planning: how land use should be split among industry, agriculture, homes, open space and commercial centers. Another governs where roads and bridges are built. A third sets out housing needs and responsibilities — for instance, how much affordable housing a community must allow.

Under the pending measure, the three regulatory and permit processes must be synchronized to meet new goals, set by the state's Air Resources Board, to reduce heat-trapping gases.

Seventeen regional planning groups from across the state will submit their land-use, transportation and housing plans to the board. If the board rules that a plan will fall short of its emissions targets, then an alternative blueprint for meeting the goals must be developed.

Once state approval is granted, or an alternative plan submitted, billions of dollars in state and federal transportation subsidies can be awarded. The law would allow the money to be distributed even if an alternative plan fails to pass muster.