(Photo by Lauren Parnell Marino)

Zipcar, one of the first car sharing businesses, requires users to return vehicles to the same location, so driving all the way out to Ikea for a shopping marathon or a day in Baltimore can wind up being a costly endeavor. The company is launching a new service today, though, that solves that problem with the option for one-way trips.

Unlike car2go, where drivers can leave the vehicles in any legal street spot, the way Zipcar’s new model works is that drivers choose their final parking spot in advance. It could be a lot, garage, or street spot from a network of more than 350 parking locations in the D.C. region (including Bethesda, Alexandria, Silver Spring, and Arlington) and another 50 in Baltimore. The flexible vehicles cost $5 for every half hour.

“In D.C. everyone has grounded the notion of one-way in the floating model, where you pick it up and leave it anywhere,” says Zipcar spokeswoman Lindsay Wester. “A lot of time is spent circling the block looking for parking. This takes away that anxiety.”

Another major difference from the regular Zipcar and Enterprise models is that there are no reservations afterward, so drivers can extend their trips for as long as they need (up to seven days). They can also change their final destination mid-trip and select a new spot, so long as there is one available in their preferred area, to drop it off in.

About 200 vehicles out of Zipcars’ fleet of more than 1,000 in the D.C. area will be designated for this new “flexible” service. There is no separate membership, so all current Zipcar users will have the option.

Nearly 40 percent of D.C. households don’t have a car, according to the 2011 American Community Survey, and their options for getting around without a personal vehicle keep growing (see: pool ride-sharing, car2go to Arlington) and being hampered by Metro (see: Metro).

“We really do think this is coming at an opportune time to support the SafeTrack maintenance issues,” Wester says.

It also gives another much-needed option for getting between D.C. and Baltimore. Currently there’s costly Amtrak and often inconvenient MARC service, which runs nine roundtrips on Saturdays and six on Sunday.

“This is an incremental step in our broader vision,” Wester says. “We want to create a comprehensive mobility solution to get people to the places they need to be, and one way is inter-city.”