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Loren Faulkner

A Traffic Tunnel System Under The Forest?
November 14, 2008

It might happen in Southern California’s Cleveland National Forest. Tests are being conducted in the Santa Ana Mountains just south of the 91 Freeway Corridor between Orange County and Riverside County. Some 250,000 motorists per day make trips through the 30 mile stretch of 12 lane freeway. But traffic during peak morning and afternoon commutes means slow going, earning it the title of one of the most congested freeways in the U.S.

To make matters worse, cheaper housing and land to the east in the Inland  Empire area have caused exponential growth. And truck traffic carrying goods from the port of Los Angeles continues to slow things down. Projections are that by 2030 some 22 lanes will be needed to handle the increased traffic. But topography and costs keep that from being a viable option.

Orange and Riverside County Transportation Commissions are looking into the possiblilty of boring two 50 ft. diameter, 11.5 mile-long traffic tunnels at a depth of 1,500 feet. The mountains rise between 2,500 and 5,000 feet above sea level. Costs have been estimated at up to $8.5 billion for this alternative traffic route. If completed, it would divert 70,000 vehicles per day away from the 91 Freeway.

One worry is that the Lake Elsinore and Whittier earthquake faults run near where the tunnels would be bored. But test engineers have assured that they would not cross through where the tunnels are projected to be excavated. And they are relatively certain an earthquake would do very little damage to a tunnel system at that depth underground.

So far, tests have shown the tunnels are actually feasible. A formal report will be issued soon, but it would still be years before work began, even if the money were available and approvals were given next week. Not likely to happen.

But something has to be done there. If I had a nickel for every time I’ve driven through that 91 Freeway Corridor at 10 to 15 mph, bumper to bumper, over the years, I could take a week’s vacation—an exaggeration, of course, but if you’ve been stuck in that corridor, you know exactly what I mean…

Posted by Loren Faulkner on November 14, 2008 | Comments (0)