Stuck in carpool gridlock

In the never-ending world of one-upmanship between Northern and Southern California, it seems the Bay Area is the undisputed winner in one category: carpool lanes.

The California Department of Transportation created a carpool system for Southern California that is vastly different from the setup in Northern California and different from the systems used for many urban freeways nationwide.

Although the public doesn’t get to vote on the kind of carpool system it wants or even whether it wants one, I would guess that there’s a large amount of dissatisfaction with the arrangement in Southern California, based on the large amount of e-mail I get on the subject.

The criticism is directed at two essential parts of the system: the restricted access to the carpool lanes and the widespread public confusion over the way Caltrans has chosen to mark the lanes.

If you have ever ventured onto the freeways that traverse and surround San Francisco, you know that the carpool lanes there revert to general use during off-peak hours, meaning they are reserved for carpools only for several hours in the mornings and evenings.

By comparison, in Southern California, carpool lanes are off limits to vehicles with only one person during all hours of the day and night.

As part of that system, Caltrans elected to restrict access to local carpool lanes to designated areas, whereas in the Bay Area and many other cities across the nation drivers can enter and exit carpool lanes anywhere they want.

What’s going on? How did Caltrans come up with two completely different systems for two densely populated urban areas in the same state? The decisions about these issues were cast in stone far back in history and it’s hard to know whether they are still valid.

Frank Quon, deputy director for Caltrans freeway operations for Los Angeles County, which is the agency’s District 7, says Caltrans set up our system based on the long periods of peak demand that occur.

“There is a high demand throughout the day,” Quon said. “Here, we have morning, midday and afternoon peaks.”

By contrast, San Francisco has more condensed peak usage and it makes more sense to release the carpool lanes to general use in off-peak hours, the logic goes.

If it was true at one time, a lot of people probably don’t buy that now.

The 101 from downtown San Francisco to the airport and through Silicon Valley can be a parking lot any hour of the day. The same goes for the freeway network on the east side of the Bay Bridge.

A separate issue for Southern California involves the decision to restrict access and egress from the lanes only at designated openings. “The regional consensus was to do it in this fashion,” Quon said.

The rationale was that it allowed carpool lane traffic to move faster. Maybe that’s true sometimes, but in heavy traffic you see bunching and crowding at the access points as drivers try to get in and out of the carpool lane trap.

And in heavy fast traffic, it’s hard to transition from the carpool lanes to the next exit. Caltrans allowed 500 feet per lane when it designed the system, but it upped the design standard to 600 feet per lane when speed limits were increased from 55 mph to 65 mph.

It seems many of the freeways still conform to the old design standard, however.

A big related problem with this system is the public confusion involving carpool lane markings. In most cases, the lanes are separated by one set of solid double yellow lines with a single solid white line. In other cases, there are two sets of solid double yellow lines and a solid white line.

I have received many letters from readers saying they believe the existence of the white line makes crossing the double yellows legal. In California, it is not illegal to cross a single solid white line when it is used by itself to mark a lane.

But it is clearly illegal to cross the yellow lines of a carpool lane. The law is set down in Section 21655.8 of the California Motor Vehicle Code. The solid white line is used in carpool lanes to define a legal lane to the left of double solid yellow lines, a rationale that is almost certainly lost on the vast majority of the public.

Another peculiar marking is the frequent use of two sets of double solid yellow lines. Caltrans uses the marking to create a buffer zone between general use lanes and carpool lanes, Quon said. But it is illegal to cross either one or two sets of double yellow lines.

Under the Uniform Manual on Traffic Control Devices, the federal bible on road markings, double white lines could be used to separate carpool lanes, Quon acknowledged. Some states, such as Oregon, use double solid white lines to forbid drivers from changing lanes on bridges. Without doubt, double solid white lines are also not well understood by the public.

But based on my mail, the current system seems to have left widespread public confusion. The California Highway Patrol hands out 19,000 citations each year for illegally crossing those lines, and at least some of those tickets went to people who simply don’t understand the system.

Ralph Vartabedian can be reached at ralph.vartabedian@latimes.com.