Montgomery County lacks the ridership to justify building a proposed $1.8 billion, 160-mile rapid bus system, according to a study requested by the county's Department of Transportation.

A panel commissioned by County Executive Ike Leggett recommended a "world class" ?bus rapid transit, or BRT, system that would run in dedicated lanes and resemble light rail. The system, which the panel recommended paying for with property tax increases of up to 15 percent, has been enthusiastically endorsed by elected officials like Council President Roger Berliner, D-Bethesda, and Councilman Marc Elrich, D-at large.

But Montgomery County may not need such a gold-standard system, according to the preliminary findings of the international Institute for Transportation and Development Policy, or ITDP.

Bus rapid transit ridership
Location Passengers per hour per direction
Bogota, Colombia 45,000
Sao Paulo 35,000
Porto Alegre, Brazil 28,000
Curitiba, Brazil 10,500
Mexico City 11,000
Pittsburgh 5,000
Rouen, France 1,700
Montgomery County:
Colesville Road 800  
Veirs Mill Road 280  
Rockville Pike 250  
Georgia Avenue 200  

Of the nearly 20 bus routes proposed, the four likely to have the highest ridership -- Colesville Road, Veirs Mill Road, Rockville Pike and Georgia Avenue -- would still have significantly fewer riders than one of the smallest BRT systems in the world, the study determined.

Colesville Road is predicted to have the highest ridership of these routes, but even there, most of the trips would likely be riders passing through on their way to the Silver Spring Metro station, with few riders getting on and off along the way. As a result, the ITDP recommends "lighter improvements to the existing bus system, such as a dedicated lane, but not necessarily all of the other elements that go along with gold-standard BRT."

Rockville Pike "appears to us to be the best place to start building a gold-standard BRT," the study found, since the route would travel through more urban areas like downtown Rockville and Bethesda and the under-development White Flint, as well as the busy area around the National Institutes of Health and the Walter Reed National Military Medical Center.

On other routes, though, taking a lane away from drivers to carry half-empty buses will just frustrate residents or cost a lot of unnecessary money, the study says.

County Councilwoman Nancy Floreen, D-at large, who chairs the council's Planning, Housing and Economic Development Committee, said she isn't surprised by the study's findings.

"This is suburbia," she said. "To assume that everyone is going to switch to a nice, snazzy looking bus is not particularly realistic."

But some of those who have been pushing for Montgomery County to build the system disagree with the study's premise that the system's estimated ridership should be based on the number of residents who currently take transit, a number that some county officials have placed at about 20 percent of all residents.

"If you ask people, they say, 'We're using our cars because transit doesn't serve us,' " said Elrich, who introduced the idea of bringing BRT to the county. "A different system with a better service attracts riders who aren't using transit."

Paid for by the Rockefeller Foundation, the ITDP's full study is expected to be completed soon. A representative of the ITDP did not return calls for comment.