Traffic Relief May Be Brief on 405

When Gov. Arnold Schwarzenegger stood near the base of the traffic-clogged Sepulveda Pass on Friday to announce he was fast-tracking $570 million in improvements to the San Diego Freeway, he probably drew grateful sighs from some of the region’s most hassled commuters.

The project calls for construction of a carpool lane along the northbound side of the freeway through the Westside and into the San Fernando Valley.

But transportation experts predict that any resulting relief from traffic congestion on the 405 would probably be short-lived.

“People are very rational,” said professor James E. Moore II, director of the transportation engineering program at USC. “If you build it, they will come.”

The maxim is sure to come up again as lawmakers begin debate on the governor’s much larger $222-billion construction bond proposal that would pay for more freeways as well as other infrastructure projects, including water systems and jails.

Moore and others say that even a huge boost in freeway funding is unlikely to mean any long-term declines in congestion -- especially in dense urban areas such as Los Angeles. There are simply too many people -- and cars -- in Southern California, and more are coming.

Just ask Sean McCarthy. The employment consultant, who lives in West Hills, says his southbound commute on the 405 improved somewhat after Caltrans completed carpool lanes in that direction a few years ago.

But now, it’s just as terrible as his northbound crawl.

“There’s not a perceptible difference to me,” said McCarthy, 51. “The freeway is so congested, so slow.”

Traffic on the 405 has gotten so unbearable for McCarthy’s wife, Ann, that she eschews the freeway altogether. Like many cross-mountain commuters, she now drives only surface streets to her job in Beverly Hills, her husband said.

Still, McCarthy is eagerly awaiting a new northbound lane. “If we do nothing, things will get that much worse sooner,” he said.

Indeed, transportation and elected officials contend that the improvements are worth the expense and should make the life of commuters at least a little better.

Even small improvements in freeway conditions might make a big difference on surrounding streets by reducing cut-through traffic, said Los Angeles City Councilwoman Wendy Greuel, chairwoman of the city’s Transportation Committee.

For example, commuters such as Ann McCarthy might opt for the freeway instead of cutting through neighborhoods. Greuel predicts that the new carpool lane “will have a major impact.”

Caltrans officials said adding carpool lanes to freeways generally saves users about a minute per mile. The eight-mile southbound 405 carpool lane, which opened in 2001, initially saved the average carpooling driver 18 minutes a day, said Judy Gish, a spokeswoman for the California Department of Transportation. And because people who already carpool shifted to the new lane, traffic in the regular lanes lightened and also began moving faster.

But automobile traffic is a bit like water, flowing to the path of least resistance. Once motorists learned that the 405 was moving faster, they would shift from other congested roads and freeways, Moore said. A freer-moving freeway also could prompt people to drive more -- all of which would contribute to the return of congestion.

That’s what happened after the southbound lanes opened. And Moore predicts that the 405 will just fill up with traffic again “within a year or so” after the new northbound carpool lane opens.

Caltrans officials are hoping to break ground on the 405 project by 2009 and estimate it will take a few years to complete. When it opens, the lane will connect to other completed carpool segments to the north and south -- creating a continuous stretch from Orange County, past the chokepoints near Los Angeles International Airport and all the way to Interstate 5 in the north San Fernando Valley.

The project will help “decrease the number of single-occupancy vehicles on the roadway,” said Will Kempton, statewide director of Caltrans, citing benefits such as reduced smog. “That’s why this connection is critical.”

Having a carpool lane also can help the growing region by serving more commuters, experts say. Cars may still move slowly, but more people -- encouraged to ride in carpools -- are being moved along.

Carpool lanes “can increase the efficiency of the system by a lot even if it doesn’t reduce congestion,” said professor Brian Taylor, director of the UCLA Institute of Transportation Studies.

About 40% of L.A. County’s 533-mile freeway system has carpool lanes, with an additional 114 miles of such lanes under construction, being designed or in the planning stage.

Even though the 405 project may not improve congestion by much over the long haul, transportation experts say Caltrans is still doing the right thing by trying to build fully connected high-occupancy vehicle lanes across the region.

“If you have little bits and pieces of HOV lanes, you don’t get as much benefit from it,” Taylor said. “The closer you are to developing some kind of network, the more people will use it. You create incentives to form carpools.”

Taylor argues that even if improvements were eventually undone by more cars, that’s not all bad.

Instead of staying home because they feel trapped by traffic congestion, people might go to see family, visit friends or check out that new restaurant across town. Commuters might be willing to travel farther for a job offering more pay and benefits.

“All of that means people are better off,” Taylor said.