Alexandria City Council and the Arlington County Board both moved Saturday to work in partnership to bring streetcars to the Route 1 corridor.

The jurisdictions agreed that Arlington, in the first phase of the two-phase project, will begin planning for a Route 1 streetcar line in 2013 that will extend from Crystal City to its border with Alexandria in Potomac Yard.

During this time, Alexandria will continue work to finalize the proposed new Potomac Yard Metro station. Alexandria will then begin the streetcar project’s second phase in 2014 by pursuing environmental and alternatives studies to assess the conversion of its portion of the Route 1 transitway from buses to streetcars.

The studies are necessary for Alexandria to secure federal funding for the project. Arlington intends to pay for its section of the streetcar line with state and local funds, including tax-increment financing in Crystal City.

Arlington County Board Vice Chairman Walter Tejada, who supported the agreement, said the jurisdictions need to continue to be upfront about the costs of the project.

"This is something we’ve been talking about for quite a while. We will need to continue to provide information to the community about where the sources of funding are going to come from ... so there is clarification if we are using local tax dollars or not," Tejada said.

Tejada said some estimates he has heard about the project cost equate to about $50 million per mile of streetcar track.

The board needs to be able to confirm or clarify this number, he said.

Arlington’s streetcar would likely be up and running in or before fiscal year 2019, while Alexandria’s streetcar extension could be operable in 2021.

The design of the streetcar segment in Arlington would not preclude a later extension into Alexandria. Planners said Alexandria’s BRT will hit the Arlington border and a smooth transition to the streetcar is possible.

The agreement doesn’t mean Alexandria will make the conversion to streetcar. Vice Mayor Kerry Donley and Councilman Frank Fannon both said they had concerns, including cost.

However, Alexandria has a better chance of securing federal funds for the project by connecting to an existing line in Arlington, said Deputy City Manager Mark Jinks.

In 2014, Alexandria would decide whether to study the streetcar extension only to the Potomac Yard Metrorail Station site or to extend the streetcar to the existing Braddock Road Metrorail Station.

“We need to keep our eyes on the prize that that’s the Metro station,” Alexandria Mayor Bill Euille said Saturday. “It’s about options. In the end, we might not do streetcar. But we have a responsibility to look at all [of the options] and make a decision at the appropriate time.”

Councilman Rob Krupicka said Saturday that some members of the community have talked about wanting to skip the Metro station and instead put that money toward the streetcar. Krupicka and Rich Baier, the director of the city’s Department of Transportation and Environmental Services, said the funding line that has been established to build the Metro station cannot be transferred over to streetcars.

“The money is not fungible in the sense that you cannot move it from Metro to light rail,” Krupicka said.

Baier said that the streetcar is geared more to a “sub-regional rider” within the Beltway, while Metro is meant to connect the area with the entire region.

“[The light-rail user] is not the same rider or user as Metro,” Baier said.