The Federal Highway Administrations reaffirmed its commitment to the bypass but said so much time has passed since the last environmental impact study was written the new issues must be studied.
Among those issues is the question of whether a tunnel would be superior, said the highway administration in an August 10 decision that reached San Mateo County officials and environmentalists yesterday.
"I think it's wonderful. That's what we've been advocating for a long time," said Olive Mayer, chairwoman of the Sierra Club's Devil's Slide task force.
For several months, environmentalists have pressed for a 4,600 foot-long tunnel through San Pedro Mountain rather than the bypass bisecting McNee Ranch State Park, which would replace the coastal highway that has been plagued with slides. The scenic coastal highway was closed for five months this year after is slipped several feet during heavy rains.
Caltrans is supposed to complete the reevaluation next spring but is not considered likely to change its mind.
"We'll reevaluate it any say a tunnel is too expensive," said Caltrans spokesman Greg Bayol, who added that the agency has studied the issue several times during the past two decades, each time coming to the came conclusion.
Evnironmentailsts say two-lane bypass would not only damage the state park but could easily be expanded to four lanes, accommodating development down the coast.
An injunction prompted by a lawsuit by environmentalists has held up constructions since September 1986.
Construction of a tunnel would jeopardize federal funds, said Jeffrey Brooks, regional director of program development for the highway administration.
He said Congress originally allocated money -- about $70 million -- for the bypass and that a new congressional appropriation would be needed to build the tunnel.
But Ted Lempert, president of the San Mateo County Board of Supervisors and a tunnel supporter, said he has been told by other federal official that money might be available from a special fund for disaster relief.
In April, the Board of Supervisors voted 3 to 2 in favor of a bypass.
Mary Griffin, one of the supervisors who supported the bypass, issued a statement yesterday saying she favors either a bypass or the tunnel, whichever is cheaper, faster to build and has the least environmental impact.
In an interview, she said that the statement does not represent a change in her position and that she voted to preserve the bypass option last April because she feared consideration of a tunnel would jeopardize the financing.
Griffin, who faces a tough reelection campaign next year, has been under intense pressure from environmentalists to support a tunnel.