SACRAMENTO -- Gov. Arnold Schwarzenegger said Thursday that traffic patterns in Oakland's MacArthur Maze -- following a fiery gasoline tanker crash that damaged interstate freeways -- will return to normal on June 29.

The governor said the state will award an emergency contract in four days for replacement of the collapsed Interstate-580 ramp in the freeway maze, requiring work to be finished no later than June 28.

Under the plan, the last of the interstate connectors damaged by the accident last Sunday would reopen to traffic the next day -- Friday, June 29. The contractor will have fiscal incentives to complete construction earlier.

The governor said at a Capitol news conference that the lower, salvageable Interstate-880 ramp will be repaired and open to traffic in as little as six to nine days.

Once the lower I-880 connector is back in use, the ramp will remain open during daytime hours to minimize impacts on commuters. There will be intermittent closures of the connector some nights to accommodate the overhead construction on the I-580 ramp.

"No time will be wasted in restoring this vital artery to the Bay Area," Schwarzenegger said in a statement. "Construction crews will continue around-the-clock repairs so that this roadway opens as soon as possible."

Caltrans officials said the advertising period for the I-580 ramp replacement has been shortened to four days, with bid opening set for Monday at 10 a.m. The project will be awarded later that day, with construction set to begin the next day.

Knowing when the Bay Area's biggest bottleneck should be fixed is a relief, said Randy Rentschler, spokesman for the Metropolitan Transportation Commission.

"It's good that Caltrans has a target date to get this accomplished; that's good news for the Bay Area," Rentschler said. "It's also good that there's an incentive in the contract so that the project can get done sooner."

Rentschler said he believes that public transit agencies can sustain this week's increased service, such as longer and more frequent BART trains, for the full two months if needed.

State transportation officials began calling for bids Thursday as part of Schwarzenegger's self-proclaimed "fast-track" approach to the job.

The state Transportation Department has authorized up to $20 million for the contract, but Caltrans expects the final cost to fall below that figure.

To restore "the economic benefits of moving goods and people on this roadway," a Caltrans official said, the contract provides incentives of $200,000 for every day the contractor finishes ahead of June 28.

On the other hand, if the project does not proceed well, the firm that wins the bid for the contract will be penalized $200,000 for every day the completion is late.

Custom-made steel girders and beams will be used, and sufficient steel and other materials are available, according to Caltrans.

The winning low-bid contractor will come from a short list of pre-qualified, competent bidders who have demonstrated their ability to build bridges and freeways in California.

State officials said they will also encourage small business participation as subcontractors in the reconstruction work.

Staff writer Erik N. Nelson contributed to this story.

Contact Steve Geissinger at sgeissinger@angnewspapers.com, 916-447-9302.