As Los Angeles County pumps billions of dollars into its expanding commuter rail network, a different kind of mass transit has become an unlikely hero of the San Fernando Valley.

The 7-year-old Orange Line, a 14-mile east-west busway connecting North Hollywood to Warner Center, has been a less-flashy workhorse of success for the Metropolitan Transportation Authority.

Less than a year after its opening, the Orange Line busway’s projected ridership more than tripled to 22,000 a day, and a study by UC Berkeley researchers found it even slightly helped relieve morning traffic on the 101 Freeway, which parallels the busway. By May of this year, daily ridership had climbed to 26,670 on a line that was significantly cheaper to build than it’s light-rail counterparts, such as the Blue, Green and Gold lines.

“It’s much easier to ride this than it is to drive,” said Gale Johnson, 52, a retired security worker who lives downtown and was riding one of the busway’s sleek, extra-long buses to a doctor’s visit in Van Nuys. “It’s like a train on wheels.”

This week, officials will open a $180-million extension, cutting north across the Valley to Chatsworth. Transit officials will tout the relatively low-cost strategy to help relieve a chronically congested corridor.

But the achievement of the Orange Line is focusing new attention on a larger question: Should rapid buses be playing a more prominent role in L.A.'s mass transit future?

“The Orange Line and Metro Rapid are so successful that it ought to lead to more commitment in that direction,” said Martin Wachs, a transportation researcher at Rand Corp. “It can complement the rail investments by extending their reach, just as the Orange Line has done.”

There has long been debate about whether L.A.'s rail boom is coming at the expense of bus service, which is still how about 78% of mass transit users get around. Conflicts over investment priorities have spilled into court and prompted a 1996 federal consent decree that required the agency provide more bus service to low-income and minority residents.

More than a dozen rail projects and over 30 freeway improvements are included in Metro’s $298-billion long-range plan. But, other than the 4-mile Orange Line extension, the plan envisions only a few new dedicated, fast-bus projects, including one that would restrict parts of Wilshire Boulevard to buses between downtown and the Westside.

Elected officials and Metro planners say they are doing what they can to improve bus speeds. Los Angeles leads the nation in so-called bus rapid transit lines — service that runs in dedicated lanes, partially in bus-only lanes, or on traditional surface streets but using signal-control technology to get through intersections faster. Metro operates 23 such bus lines that cover about 400 miles and carry 245,000 daily passengers.

The differences for bus commuters can be significant. During the morning rush on Wilshire Boulevard, for example, Metro’s rapid service runs about 36% faster than the regular bus line. And the Orange Line averages about 20 mph during morning rush hour, nearly twice the speed of the Wilshire local line.

Rapid bus lines are more common in other countries. Curitiba, Brazil, considered the birthplace of the concept, was the inspiration for the Orange Line. L.A. County Supervisor Zev Yaroslavsky said he sketched the idea for the Valley busway on an airplane napkin while returning from a visit there in the 1990s.

Originally, officials envisioned a light-rail line running across the Valley, using an unused rail right of way. But after years of delays, the switch was made to a busway to save money.

Such bus routes remain rare in the United States. New York City has three rapid bus lines, and Chicago is implementing its first this fall.

Decisions on whether to invest in bus rather than rail improvements are often influenced as much by public perception and politics as by what will best serve the needs of communities, some transit experts say.

“I think that’s part of the problem. That there’s an old stigma that a bus is an old, smelly, crowded vehicle and a train is a new, fast, shiny one,” said Dennis Hinebaugh of the National Bus Rapid Transit Institute.

Adds Rand’s Wachs: “There’s many cities in the world where people go to the opera on the bus. That’s not necessarily true in Los Angeles.”

Metro planners say they hope to identify several more corridors where fast-bus strategies can be deployed. But when and how those will be funded and implemented isn’t clear.

And comparing costs of rapid bus lines and rail isn’t simple, officials say. Rail costs more to build but can be less costly to operate, they say. That’s particularly true as ridership grows, they add, because fewer employees can move many more passengers. They also note that some Metro rail routes, notably the Blue Line from downtown L.A. to Long Beach, and the Red Line from downtown L.A. to North Hollywood, carry significantly more riders than the Orange Line.

However, Wachs argues that the cost of a rapid bus line actually is lower overall compared with rail. He said the assumption that rail lines have lower operating costs doesn’t pan out, partly because a good rail system must have an extensive network of buses feeding into it. He supports rail projects, particularly in the core of the transit system, but said that large numbers of commuters would benefit from a greater emphasis on fast-bus improvements.

For many riders, getting where they need to go as fast as possible is a bigger concern than whether they ride a train or bus.

“It’s almost the same thing, just this one’s outside and the other’s a subway,” said roofer Freddy Fernandez, 24, comparing the Orange Line to the connecting Red Line underground. “It’s a smooth ride. It crosses through everything.”

Yaroslavsky and other Metro officials are dubious about how much more rapid bus expansion can occur in L.A.

There are few remaining places with dedicated rights-of-way, like the old rail corridor that made the Orange Line possible. And, as the controversial Wilshire bus lane project has shown, it’s politically difficult to take space away from cars in traffic-clogged corridors.

“I think we could grow it somewhat,” Yaroslavsky said, noting that Orange Line buses often run so frequently they “are on top of one another.”

If the busway’s popularity continues to grow, he said, it may need to be converted to a rail line.

ari.bloomekatz@latimes.com