A plan to build a streetcar system along Columbia Pike in Arlington and Fairfax counties is poised to move forward this week as part of a years-long plan for developing the busy corridor.

Metro officials are slated to vote Thursday on whether to begin a $4.06 million environmental and engineering study of the proposed 5-mile streetcar line. It would be the first major step needed before financing and building the line with its 14 proposed stations between the Skyline complex and the Pentagon City Metrorail station.

“We’re quite enthusiastic about it in Arlington,” said Christopher Zimmerman, an Arlington County supervisor who sits on Metro’s board of directors. “For us, it’s one of our top transportation priorities in Arlington. It’s critical to the development planned in the corridor.”

The project would consist of an electric tram that runs on embedded tracks in one lane of the roadway, making stops along the curb.

Arlington and Fairfax counties chose the system in 2006 as a way to carry more passengers than the buses that already run along the busy pike. A streetcar wouldn’t need a dedicated right of way like Metrorail would.

Earlier this spring, the two counties approved the initial money that allocates $3.8 million for a consultant to study the environmental effect and draw up preliminary engineering. An additional $260,000 would go to Metro to manage the project. But the transit agency still needs to weigh in on the plan.

Zimmerman hopes the line can be the first piece of a network of surface rail that would include a link to Potomac Yard and Crystal City.

But some say Northern Virginia has more important transportation priorities amid the tight economy.

“We have billions and billions of needs and to put a couple hundred million dollars in Columbia Pike seems a poor investment at this time,” said Bob Chase, head of the nonprofit Northern Virginia Transportation Alliance.

The total project costs vary somewhat, with preliminary estimates of $160 million to $175 million. Who will pay for the construction hasn’t been established. But the environmental study could help qualify the project for federal funding.

It’s also not clear who would operate the system and who would pay the operating costs. Zimmerman projects the earliest it could be running would be about 2014.

Streetcars, light rail projects renewed

Arlington, like communities around the country, once had a network of streetcars. Today such transit lines are making a comeback in many jurisdictions. Locally, similar projects are also being planned, including a streetcar line in Anacostia and a possible line between Crystal City and Potomac Yard. Meanwhile, Maryland is considering options on how to build a Corridor Cities Trans-itway from the Shady Grove Metro station to Clarksburg and the proposed Purple Line between Montgomery and Prince George’s counties.