Despite calls to scrap its $249 million plan to run streetcars along a 5-mile stretch of Columbia Pike, members of the Arlington County Board say they're committed to moving forward with the project.

Many in Arlington still support the use of streetcars, members said, even though a movement is underway to replace the planned streetcars with buses, a proposal that is picking up support in a three-way race for a seat on the county board.

Board Chairwoman Mary Hynes said the board, which chose to use streetcars instead of buses after more than 10 years of study, believes streetcars "will deliver for the long-term better than a bus system."

A new 33-page study examining the differences between buses and streetcars found that "a modern bus-rapid-transit system is far superior to streetcars in the Columbia Pike Corridor."

The study, done by Peter Rousselot, a transportation consultant and former chairman of the Arlington County Democratic Committee, concluded that buses would be one-half to one-fifth the cost of streetcars and would allow for more stops along the highway.

"The appropriate critical studies have not been done," the report said of the county's move toward streetcars. "Neither Arlington citizens nor Arlington businesses, which must pay for the streetcar, have been informed of the options available for the transit system they will fund."

But Juliet Hiznay, president of the Columbia Pike Revitalization Organization, defended the streetcars as a better long-term investment for the county.

"I'm not sure we can purely look at this from a cost perspective," Hiznay said. "If you look at what the upsides are in terms of economic investment in the region, light rail is the answer. They create a more walkable, more interesting environment and promote business."

The organization issued a report of its own in response to Rousselot's study that concluded that the choice of streetcars over buses was the "correct and well informed" decision.

"There have been so many opportunities for public comment," Hiznay said. "It seems peculiar to be seeing this kind of report at this time."

The line, slated to run from Pentagon City to the Skyline area of Fairfax, could begin operating as early as 2016. Arlington would pay most of the $140 million local share of the streetcar costs since 16 of the proposed 19 streetcar stops are in the county. The project would require $75 million in federal funding and $35 million from the state.