OAKLAND, Calif. - Bay Area commuters skirted the wreckage of a collapsed section of freeway yesterday as crews began hauling away the charred debris that had been a vital link between San Francisco and its eastern suburbs.

The snarled highways envisioned for the region did not materialize in the morning, as many commuters took advantage of free public transportation, avoided rush hour, or just stayed home. Officials had worried the afternoon drive would create headaches as traffic leaving San Francisco was diverted from the collapsed eastbound segment. But yesterday afternoon was like a normal weekday commute, California Highway Patrol officials said.

The crash occurred on the MacArthur Maze, a network of ramps and interchanges at the edge of downtown Oakland and about a half-mile from the San Francisco-Oakland Bay Bridge toll plaza.

The elevated section of highway that carries motorists from the bridge to a number of freeways was destroyed early Sunday when the heat of a burning gasoline tanker truck - exceeding 2,750 degrees - weakened part of one overpass, crumpling it onto another. The truck's driver walked away with only second-degree burns; no other injuries were reported.

Authorities predicted that the crash would cause the worst disruption for commuters since the 1989 Loma Prieta earthquake damaged the Bay Bridge.

About 80,000 vehicles a day used the damaged portion of road. But because the accident occurred where three highways converge, authorities said it could cause problems for hundreds of thousands of commuters. State transportation officials said 280,000 commuters take the Bay Bridge into San Francisco each day.

To encourage motorists to switch to public transit, Gov. Arnold Schwarzenegger authorized free passage yesterday on ferries, buses, and the BART rail system. Extra trains were added, and bus and ferry operators also expanded service.

Inspectors X-rayed about a dozen pillars supporting the ramp near the collapsed section to see whether they could be salvaged, said Jeff Weiss, a spokesman for the California Department of Transportation.

Originally built in the 1950s, the collapsed roadway was retrofitted in the late 1990s to withstand quake damage. Engineers are likely to overhaul the interchange to meet today's more stringent seismic standards.

State officials promised to move swiftly, and observers said the span could be rebuilt in a matter of months.

The repairs are likely to cost tens of millions of dollars. Will Kempton, director of the California Department of Transportation, said the state was seeking federal disaster aid.

The investigation was still under way, but the California Highway Patrol believed driver James Mosqueda, 51, might have been speeding. Investigators were examining scrape marks and other evidence, CHP Officer Les Bishop said. Investigators did not suspect that alcohol or drugs were involved, Bishop said.

Mosqueda has a history of criminal activity, including drug and burglary arrests, and served more than two years in prison on a 1996 arrest for heroin possession, court records show. The state's vehicle code lets convicted felons who have served their sentences get commercial driver's licenses so long as they have clear driving records, Patrol Chief Steve Vaughn said.