Cars slow to a standstill outside Bethesda's Walter Reed National Military Medical Center most evenings, turning Rockville Pike into a parking lot.

The stop-and-go traffic inching along one of the town's busiest roadways has grown only worse with the addition of thousands of military workers transferred to the medical center seven months ago while state, federal and Pentagon officials wrangled over who would pay for the road improvements needed to accommodate the extra cars.

"We moved here two years ago from Chicago. I thought Chicago traffic was bad. I've never seen anything like this before," said Rachel Seeger, who lives nearby on Connecticut Avenue.

And starting Monday, an effort to improve the traffic situation will, for a while, only make it worse.

Crews will begin to close lanes along Rockville Pike near Walter Reed and the National Institutes of Health to add turning lanes to the road's intersection with Cedar Lane.

But the situation is already so bad that NIH employee and Bowie resident Lisa Washington is considering moving closer to work.

"It's very frustrating," she said. "It definitely makes me want to move into the area."

Similar problems are playing out in Alexandria and Fairfax County, where thousands of additional defense workers were relocated last fall as part of the Base Realignment and Closure process, or BRAC, before roads were prepared for their arrival. And local officials blame the federal government and Pentagon for poor planning and penny pinching that they said has only exacerbated the region's notorious traffic problems.

"We did everything we could locally, but without federal and state funds there was no way we could go anywhere," said Montgomery County Executive Ike Leggett. "The funding for it was tied up in Congress for such a long period of time."

Congress provided $90 million to Maryland to help unclog the roads, and state officials plan to add another lane along Connecticut Avenue between Jones Bridge Road and the Beltway, and to add turning lanes to the intersection at Rockville Pike and Cedar Lane. Upgrades for bicyclists and pedestrians also are planned. But the work will take years to complete.

Some commuters are switching to Metro, which has already seen an additional 1,000 riders a day at the Medical Center station across Rockville Pike from the military hospital. A $40 million pedestrian tunnel is now planned to connect Metro with the military facility, though work on it won't start until fall 2013.

The situation is similar across the river in Alexandria, where southbound traffic on Interstate 395 slows near the new Mark Center offices along Seminary Road. Work on an $80 million traffic ramp will begin there in the spring of 2013.

Further south, crews will begin work this summer on a new ramp connecting Interstate 95 to the new Fairfax County headquarters of the National Geospatial-Intelligence Agency, which added 8,500 workers to local roads.

Those frustrated by the congestion just want it gone, including Ibrahima Diallo, manager of Besta Pizza in Bethesda, whose deliveries are sometimes late because of traffic.

"I hope it's not going to stay longer than it takes," he said. "I hope they're going to finish soon."