Caltrans crews bulldozed through the final few inches of rock in a San Mateo County hillside Friday, reaching a major milestone in the completion of two tunnels that will reroute state Highway 1 away from a treacherous piece of roadway called Devil's Slide just south of Pacifica.
When finished in 2012, the Devil's Slide Tunnels Project will eliminate the region's susceptibility to isolation during winter storms, which have caused rockslides and slips with devastating impacts on access to and from several coastal communities, including Half Moon Bay, Montara and Moss Beach.
"This is a thrilling and historic milestone," Caltrans Director Cindy McKim said.
"We are well on our way to completing these tunnels and ending, once and for all, road closures that have impacted the local communities."
Crews have excavated two tunnels beneath San Pedro Mountain - each just over 4,000 feet long - since Caltrans broke ground on the project in Sept. 2007. About 240,000 cubic yards of soil have been removed.
Following the excavation, Caltrans sprayed exposed rock with shotcrete, a form of concrete, and installed steel lattice girder reinforcements. They then applied a yellow waterproof membrane layer followed by a final lining.
The construction method, known as the New Austrian Tunneling Method, is being used for the first time in the construction of a tunnel in California.
A highway tunnel has not been completed in California since 1964, when the Caldecott Tunnel was finished in Alameda County.
The new roadways are expected to cost $300 million, plus $42 million for the construction of two single-lane bridges that connect to the north tunnel portals near Pacifica.
The project was paid for entirely with Federal Emergency Highway Relief Funds. The existing portion of Devil's Slide and Highway 1 that will be bypassed by the new tunnels will become a public hiking and biking pathway with approximately 80 acres of public space.
"We're very grateful," Half Moon Bay Mayor Marina Fraser said at the punch-through ceremony, as she presented Caltrans District 4 Director Bijan Sartipi with a pumpkin on behalf of her city.
"This road has been so undependable for us," she said.
U.S. Rep. Jackie Speier, D-San Mateo, added, "When it comes to Devil's Slide, we'd like a lot less of exciting times."
"This tunnel will become a major landmark," she said.
Also in attendance at this afternoon's event were state Sen. Leland Yee, D-San Francisco/San Mateo, Assemblyman Jerry Hill, D-San Mateo, San Mateo County Supervisors Rich Gordon and Rose Jacobs Gibson, Pacifica Mayor Sue Digre and Mayor pro Tem Mary Ann Nihart, and former Chief of Staff for former Rep. Tom Lantos, D-San Mateo, Evelyn Szelenyi.
Lantos, who died in 2008, was widely credited with securing federal funding for the Devil's Slide bypass project. Caltrans intends to call the roadway the Lantos Tunnel in his honor.