The new tunnels at Devil’s Slide on the northern California coast are finally open to drivers. This marks the first time cars have driven through a brand-new California highway tunnel in almost 50 years. The Devil’s Slide tunnels, officially named the Tom Lantos Tunnels, have been under construction since 2007 but have been a source of controversy since the 1970s.
When Highway 1 was built along the California Coast in the 1930s, it included a 1.2 mile stretch of road on an extremely unstable piece of hillside between San Francisco and Half Moon Bay called Devil’s Slide. During especially rainy winters, the ground would give way, causing the road to break and forcing drivers into a 45 mile detour. In 1995, the road was closed for 158 days.
Since the 1960s, California’s Department of Transportation, or Caltrans, had been looking for an alternative route. Caltrans proposed a highway bypass that would cut through the coastal hills. Locals and environmental activists were vehemently against the bypass, which would have been a larger freeway and split Montara State Park. The groups successfully used the National Environmental Policy Act and the California Coastal Act to postpone construction of the bypass through the 1970s and 80s. At the same time, the groups fought for a tunnel as the solution to the Devil’s Slide.
Caltrans had originally said that a tunnel would be too costly, but an independent study in 1996 showed that the tunnel was “reasonable and feasible.” In November of 1996, 74 percent of the voters of San Mateo County approved an initiative that stated a tunnel was the only permissible repair alternative to Devil’s Slide.
Construction began in 2007. The tunnels are over three-quarters of a mile long, with a total of 32 ventilation fans. The project’s cost of $439 million was fully funded with Federal Emergency Relief money, secured by U.S. Representative Tom Lantos, the tunnel’s namesake.
In a press release, Brian Kelly, the acting secretary of California’s Business, Transportation and Housing Agency, praised Caltrans and the other groups that worked to make the tunnels a reality.
“Ingenuity, will, and perseverance combined to get this project done. The new tunnels are state of the art structures that blend well into the beautiful, natural surroundings on this stretch of Highway 1,” he said. “Thanks to the work of the men and women who dedicated themselves to completing this project, motorists and emergency responders will have a safer journey from this day forward.”