Less than a week after one transportation agency dropped plans for a controversial diamond lane on the Ventura Freeway, another group of Southern California transportation officials took the first step last week toward the possible creation of a similar lane on the San Diego Freeway.
The Los Angeles County Transportation Commission voted Wednesday to form a committee to study whether lanes restricted to car pools and buses are feasible on Interstate 405 between the Ventura Freeway and Orange County.
The committee will focus on ways to use lanes to be added in five upcoming widening projects on the San Diego Freeway, commission staff members said. No existing lanes will be converted to diamond lanes, officials said.
Of the five projects, the largest is slated for the South Bay area, where a 13-mile stretch between the Marina and Harbor freeways will be widened from four to five lanes in each direction.
A similar committee studying the Ventura Freeway recommended last month that a new eastbound lane to be added by 1990 between the Hollywood Freeway and Topanga Canyon Boulevard be a diamond lane.
But the margin of approval was so close that state Department of Transportation officials promptly announced they were abandoning the plan. Instead, both the eastbound and westbound lanes will be open to all vehicles.
Caltrans officials said the committee's 22-20 vote, with three votes cast for no widening, failed to demonstrate the wide consensus needed to launch a diamond lane.
They also cited receipt of 12,000 letters opposing the diamond lane as a reason for dropping the plan.
Caltrans' decision was a setback for traffic planners, who regard diamond lanes as an effective means of increasing the capacity of the region's freeway system at a time when construction funds are scarce.
Also a setback for proponents of diamond lanes was a 4-0 vote two weeks ago by the Los Angeles County Board of Supervisors, with Kenneth Hahn absent, against the proposed Ventura Freeway diamond lane.
Traffic planners said the supervisors' vote suggested there might not be political support for future diamond lane proposals.
Nonetheless, Rick Richmond, executive director of the commission, which has veto power over Caltrans on highway projects, said commissioners, by creating the San Diego Freeway advisory committee, "reaffirmed our general interest in seeing an expanded use" of diamond lanes.
The 11-member commission is composed of the five supervisors plus elected officials from cities within the county.
Three diamond lanes are in operation in Southern California, and Caltrans planners have tentatively identified a dozen freeways in the region where such lanes might be added.
Traffic engineers said that diamond lanes on the Costa Mesa and Artesia freeways have induced substantial numbers of motorists to form car pools or ride buses, thereby reducing congestion.