OAKLAND, Calif. (AP) -A highway ramp shut down by the collapse of an overpass near the San Francisco-Oakland Bay Bridge won’t have to be rebuilt from scratch, state transportation officials said Wednesday.

The ramp connecting two interstate highways was blocked Sunday morning when a burning tanker truck brought down the overpass. Crews finished clearing debris from the collapse Tuesday.

Investigators found that the steel girders holding up the lower ramp had warped but remained structurally sound and could be straightened, California Department of Transportation spokesman Bob Haus said.

The department would not predict when the roadway would reopen. Engineers were still assessing damage to the ramp’s concrete deck, Haus said.

The overpass connecting eastbound Interstate 80 to eastbound Interstate 580 was destroyed by the tanker explosion, however, and will have to be replaced.

Traffic over the bridge into San Francisco on Wednesday morning was at its worst since the collapse, but rain and several minor accidents appeared largely at fault.

The gridlock feared by authorities has failed to materialize, but detours along Oakland streets have raised concern among residents about the increased traffic and pollution.

Meanwhile, the Bay Area Rapid Transit rail system reported record ridership Tuesday with more than 375,000 passengers, up from an average weekday ridership of 340,000.

The truck’s driver, James Mosqueda, 51, of Woodland, remained hospitalized in San Francisco in fair but stable condition.

No criminal charges or citations have been issued as a result of the accident. The California Highway Patrol said it is investigating the driver, the company that owned the truck and the vehicle’s safety record.