The proposal for what would be the world's second-longest road tunnel would create a new path between sprawling inland suburbs and Orange County, which has become one of southern California's fastest-growing job centers.
The tunnel would rank second in length to Norway's 15-mile Laerdal Tunnel, which opened in 2000, said Michael Litschi, spokesman for the Orange County Transportation Authority. There are longer railroad tunnels, including the 33.5-mile Seikan Tunnel in Japan and the 31.3-mile Channel Tunnel linking England and France.
Local officials have worked closely with a British engineering company that has helped build some of the largest tunnels in the world and has concluded that the tunnel is "viable and feasible," said H. Tony Rahimian, a consultant who helped devise the tunnel proposal.
"A tunnel is actually a very safe place. We don't want to run it through the faults and we're going to avoid that," he said.
But critics question the logic of building a multibillion-dollar project in a region so prone to earthquakes that an alternate proposal for a double-decker highway was deemed too dangerous. The tunnel would begin barely a mile from a fault that produced a 6.0-magnitude earthquake about a century ago.
"It's absolutely absurd to have a tunnel 700 feet below ground in earthquake country," said Cathryn DeYoung, mayor of Laguna Niguel and a vocal opponent. "I mean, would you want to be in that tunnel?"