AP Photo/Eric Risberg
Devil's Slide tunnel project in Pacifica, Calif. Wednesday, Feb. 13, 2013.
PACIFICA, Calif. — Two slick new mile-long tunnels are undergoing final safety tests this month, poised to divert motorists away from an ocean cliff-hanging roadway dubbed Devil's Slide south of San Francisco to a smooth, Alpine-like passageway unlike any in the U.S. today.
The $439 million project, paid with federal emergency funds, features massive exhaust fans, carbon monoxide sensors and a pair of 1,000-foot bridges soaring 125 feet above a grassy horse ranch. A series of 10 fireproof shelters are staggered between the double bores, and remote cameras dangle from the ceiling, monitored by an around-the-clock safety staff of 15.
The tunnels, the first in the U.S. designed and built with an Austrian technique, have a Euro-glossiness to them, with white, glistening walls and shiny pipes gliding down a rounded ceiling. There's a bit of theme park vibe as well, with retaining walls and fake boulders at the entrance sculpted by the man who shaped and molded Disneyland's Indiana Jones ride.
"A new highway tunnel is a rare beast in this country, and what they are doing at Devil's Slide is certainly different than anything we've seen in the U.S.," said Neil Gray, director of government affairs at the Washington, D.C.-based International Bridge, Tunnel and Turnpike Association.
The Tom Lantos Tunnels, named after the late congressman, are the first tunnels built in California in more than 50 years. There are only a handful of tunnels under construction in the U.S. today, including the Alaskan Way Tunnel in Seattle, and the fourth bore of the Caldecott Tunnel, just 34 miles east of Devil's Slide in the eastern San Francisco Bay area.
Unlike those tunnels built to relieve commuter congestion, this new pair, 15 miles south of San Francisco, will divert a treacherous 1.2-mile stretch of the Pacific Coast Highway that constantly erodes and frequently collapses.
It's a spectacular section of road that was never meant to be.
Just three years after its 1937 completion, the road tumbled into pounding waves below. The road has fallen eight times since, causing costly closures that have devastated communities to the south — Montara, Moss Beach, El Granada, Princeton and Half Moon Bay — that depend on the route for daily commutes and for tourism from motorists heading south from San Francisco.
Each closure turns a 7-mile scenic drive from Pacifica to Montara into a 45-mile detour through the hills, and some have lasted for months.
In addition to slides, every year there are serious — often deadly — accidents on the narrow roadway, which twists so sharply that safe drivers are forced to slow to less than 25 mph. Reckless motorists have plunged hundreds of feet down the cliffs or drifted into oncoming traffic, resulting in horrifying head-on collisions. Plans are to turn the road, once closed, into a pedestrian and cycling park.
MORE: The World's 10 Most Amazing Tunnels
From our partners
Completed in 1936, the Yerba Buena Tunnel connects the two stretches of the San Francisco-Oakland Bay Bridge. With a diameter of about 76 feet, it remains the world's largest single-bore tunnel and carries five lanes of traffic going each way, one over the other. (NASA/Wikimedia Commons)