Montgomery County penny pinchers might not want to spurn expensive homes surrounding Metro stations.

In some cases, households fork over twice as much cash annually for transportation than those in more urbanized areas -- mitigating any savings from cheaper housing -- according to a report released by the Montgomery County Planning Board.

Pockets of Montgomery County with lower transportation costs are generally more urbanized and Metro-accessible, while residents in lower-density areas relatively removed from job centers are paying for their open space, the report shows.

Silver Spring households, for example, spend $9,419 on transportation every year -- or half of what Potomac residents pay annually.

Gas and vehicle repairs amount to thousands of extra dollars each year, according to public transportation advocates.

Average annual transportation and housing costs

"It's astonishing," Ben Ross, president of the Action Committee for Transit, said of the transportation cost discrepancy. "People look at rents closer to Metro and say, 'How can anybody live there?' But the spending is so much less [when including transportation]. It really turns the numbers around." But rising Metro fares this year certainly will limit some of the savings.

The study ranked Bethesda, Silver Spring and Wheaton the most walkable communities, which officials also attributed to the cheaper costs.

However, the enormous gap in housing prices show that many don't mind the economic trade-off. Potomac residents pay more than three times as much on housing each year than those in Silver Spring.

Aside from Bethesda, areas without Metro access are more expensive when transportation and housing costs are combined, the yearly averages show.

The study also found two-thirds of county residents primarily drive alone during their daily commutes, and 25 percent use public transit or carpool.