High-Tech System Would Give Buses the Green Light

Imagine this: You jump on a bus. As it rumbles down the street, one traffic light after another automatically turns green, forcing cars on side streets to wait until the bus passes.

Further along, the bus stops to pick up passengers. When it’s ready to proceed, the driver no longer has to wait for a courteous motorist to let the bus back into traffic. Instead, everyone else must wait while the light allows only the bus to proceed.

Although it may not be welcome news to perennially rushed motorists, traffic engineers are planning to test a high-tech system throughout Los Angeles County that allows buses to extend a green light or shorten a red light as a way to speed bus travel and encourage public transit use.

They’re really going to make cars wait for buses? In car-crazy Los Angeles?

“It’s for the public good,” city transportation engineer Kang Hu said, assuring that the wait for motorists will be only “a matter of seconds” and barely noticeable. “A bus carries more people.”

“It’s not a situation where we’re taking lanes away from vehicles,” transportation engineer Richard Jaramillo added, citing bus-only lanes.

Maybe motorists won’t mind. After all, they didn’t rebel when Caltrans installed red lights at freeway onramps.

Actually, the system is already in use in a number of Los Angeles County cities--to speed fire engines through intersections.

Here’s how one system being studied works: An electronic transmitter installed on the front of the bus emits an invisible infrared beam to the traffic signal. The green light stays on longer or the red turns to green faster.

A motorist on a side street might have to wait an additional 10 seconds. But for a bus passenger, a 10-second savings at each intersection can significantly reduce travel time over 100 intersections.

Traffic engineers working with the Metropolitan Transportation Authority are studying what streets will be selected for the $4.8-million “bus priority pilot project.” Candidates include Wilshire, La Cienega, Crenshaw, Van Nuys and Ventura boulevards. Testing should begin later this year.

Giving buses preferential treatment at intersections is just one idea under study to promote bus ridership, which last year in Los Angeles dropped to its lowest point in recent years. A bus riders’ group has been pushing for bus-only lanes--something the city is considering for rush hour along some of the busiest bus routes downtown.

Traffic engineers also are looking at testing a special traffic light that would give buses a five-second jump over other traffic through the intersection.

Unlike the signal-priority system, which allows all traffic traveling in the same direction as the bus to benefit from the longer green lights or shorter red lights, the “queue jumping” allows only the bus through the intersection while all other traffic waits at a red light. A “T” would flash on the traffic signal, permitting only the bus to proceed.

The technology that allows police cars, firetrucks and buses to hold a green light or shorten a red light has been around for years. But it has only recently caught on as traffic engineers--facing shortages of funds and land to expand or build new roads--look for new ways to ease gridlock.

“The answer isn’t always more buses,” said Brad McAllester, the MTA’s director of mobility and air quality programs. “The question is how do we move buses smarter?”

“What the Federal Highway Administration is trying to do is divert some of the funds from road building that can’t happen anyway into electronics that help manage the roadways we have better,” said Bob Johnson, market development manager for 3M Safety and Security Systems Division. The company makes the Opticom Priority Control System, one of the systems under study by local officials.

Bus priority systems are in use, mostly in Canada and Europe, but also in a few places in the United States--Austin, Texas; Bremerton, Wash., and Charlotte, N.C., for example.

In Bremerton, transit agency spokesman John Clauson said the system has been well received. “We get the occasional call from a person feeling that the bus shouldn’t be using it when they are empty on a Sunday morning,” he said.

But one-hour bus trips have been cut 6 minutes, he said.

A similar system is being used to speed the Los Angeles-to-Long Beach trolley through intersections.

When the system was tested several years ago on Ventura Boulevard, traffic engineers ran into an unexpected problem: Bus travel improved so much that drivers slowed down so they would not end up ahead of schedule. In the future, bus schedules will be adjusted to account for faster bus trips.

Also, bus drivers forgot to flip a switch that activated the system as they approached intersections. The system can now be controlled by computer.

The Ventura Boulevard priority system was found not compatible with the computer that synchronizes the traffic lights. Engineers believe they have corrected that problem.

So can motorists buy the device?

“We only sell to government,” said Johnson.