Study Helps Carpool Lanes Get Go-Ahead

Los Angeles County is home to the largest carpool-lane system in the nation, a 420-mile web of asphalt that has been billed as a key tool for alleviating the region’s worsening traffic gridlock.

For the most part, the county’s carpool lanes have lived up to the billing. But a new analysis has found that some stretches of freeway fail to meet minimum thresholds for vehicle use, while others are so crowded that motorists save little time by using them. The analysis also found that only about one-third of the trips in carpool lanes are for work. Many more are for leisure.

Still, the study by the Metropolitan Transportation Authority--to date, the most in-depth analysis of the county’s carpool-lane system--concluded that the special lanes cut travel time for most carpoolers, encourage ride-sharing and help reduce smog.

Carpool lanes also have the support of a vast majority of the public, according to the study.

MTA officials say the study’s findings reinforce the agency’s own goal of expanding the system by building carpool lanes in nearly every freeway in the county and connecting the lanes to form a seamless regionwide system.

MTA officials plan to add nearly 250 miles of carpool lanes in the next decade.

Planning chief James de la Loza conceded that some carpool-lane segments have failed to meet specific goals established by the MTA. But he expects those lanes to improve dramatically, once the system is expanded.

De la Loza hopes such improvement will take place on the Hollywood Freeway in the San Fernando Valley. The freeway’s carpool lanes have been open since 1997, but still fail to meet the minimum threshold of 800 vehicles per hour, a goal recommended by most transportation agencies.

De la Loza said the carpool lanes on the Hollywood Freeway may be used too little because the segment is short--only 4.5 miles long.

On the other hand, the carpool lanes on the Orange Freeway between Orange County and the Pomona Freeway are so congested that travel speeds average less than 30 mph during rush hours. Carpoolers save less than three minutes in their commute compared with drivers who use other lanes of the freeway.

Experts say the time-saving benefit of a carpool lane must be sufficient to outweigh the time it takes to set up a daily carpool.

“It takes a lot of time to carpool,” said Joy Dahlgren, a research engineer at UC Berkeley’s Partners for Advanced Transit and Highways program. “You have to wait for people, to pick them up.”

Because such benefits are minimal on the Orange Freeway, the MTA study said, the economic benefit to motorists on the freeway will not surpass the cost of building carpool lanes along the freeway until 2016.

In the Orange Freeway’s crowded carpool lanes and others, De la Loza said, the MTA could try to improve traffic flow by increasing the minimum occupancy from two to at least three people per car. He said the MTA might also add more bus lines along the route.

Time Incentive Minimal

The time incentive is also minimal in the carpool lane of the Ronald Reagan Freeway in the San Fernando Valley. During peak commuting hours there, the average speed is about 70 mph, while the average speed in the adjacent lanes is 61 mph, according to the study. Motorists who carpool on this stretch save only about 10 seconds per mile.

De la Loza said that the MTA would continue to study ways to improve the county’s carpool-lane system, but that it had not imposed a deadline for meeting the agency’s goals.

The MTA study included a survey of more than 3,000 residents that found that carpool lanes are enormously popular, with 88% public support.

However, the survey found that only about one-third of carpool trips are made by people on their way to work. Nearly half of the carpools in the county are personal or social trips, such as visits to family and friends, according to the MTA study.

The study also found that about 60% of carpools consist of family members--husbands, wives and children. About 40% carry co-workers.

Alan Pisarski, author of the book “Commuting in America,” said the MTA’s survey results are not surprising.

In Southern California, he noted, commuting patterns have become diffuse, with employment centers scattered throughout the region. He said that explains why most carpoolers are spouses and children, a practice that he calls fampooling.

“It’s just getting harder and harder to put together a carpool with somebody who is going where you are going at the same time you are going,” he said.

Because of this problem, Pisarski said, he doubts that carpool use in Los Angeles County will increase substantially, even if the MTA expands and connects all the carpool lanes in the system.

Diamond Lanes Helpful

Jovany Febrez, a filing clerk from Chatsworth, is an example of a leisure carpooler. He said he doesn’t carpool to his Encino job because it’s not convenient.

But he finds the diamond lanes are a great advantage on the weekend when he, his wife and their three children hit the road in their minivan to visit family in Pasadena or Orange County.

Still, transportation experts say, carpools that include family members can help reduce congestion and smog by giving working family members the incentive to drive together instead of taking separate cars.

The MTA survey also found that residents are almost evenly divided over whether carpool lanes get enough use. Nearly half of those surveyed said carpool lanes are underused, but just as many said carpool lanes get enough use.

This perception can influence how a person feels about carpool lanes.

Tracy Fant, a Burbank administrative assistant, said the carpool lanes along her route to work always seem empty, and so she can’t imagine how they can reduce the region’s increasing gridlock.

“When you are sitting in traffic and you see an empty lane, that ticks me off,” Fant said. “It’s an extra lane that no one uses that much.”