The parking lots of Best Buy and Circuit City are about 100 feet apart in the commercial district that sprawls across Route 301 in Southern Maryland. Unless shoppers want to dodge eight lanes of traffic and hop a guardrail, though, they are forced to drive to compare prices.

Walking in that strip of Waldorf is out of the question "because it's dangerous," said frequent shopper Sonya Thomas, a government contractor from Accokeek. "I wouldn't consider it."

The shopping corridor in Charles County is dwarfed by Tysons Corner, Fairfax County's vast car-centric complex of malls and high-rises. In Waldorf, no multilevel parking structures exist. The tallest building rises five stories.

But Waldorf and other fast-growing outer suburbs of Washington are facing similar challenges. Like Tysons, they were planned with cars in mind and without much thought to people on foot.

For four miles in Waldorf, there are no crosswalks, no sidewalks and no traffic lights with pedestrian signals. Fewer than 1 percent of Charles residents walk to work, the 2000 Census found, and the same is true for Spotsylvania County in Virginia.

Now, government planners in the two outer counties -- along with proponents of the movement known as smart growth -- see an opportunity to reverse course before these newer areas evolve into versions of Tysons Corner, which itself is trying to reduce traffic.

"The more people we get, the more people ask, 'Why can't I walk or bike anywhere?' " said Spotsylvania's planning director, Richard Goss. "Everything is designed for cars."

Until a recent growth spurt, Charles's size -- 137,000 people -- and spread-out rural development did not lend itself to a comprehensive network of trails for walkers and bikers, said Planning Director David Umling.

That is changing, he said. Planners have rewritten the rules for development to encourage a series of urban-style villages where people would feel more comfortable walking to shop, eat and go to work. New roads, such as a pending cross-county connector, are required to include trails for walkers and cyclists.

The developer of a project planned for the northern tip of Waldorf also is designing a footbridge for Route 301 that could support the county's long-term vision for a light-rail line and station.

What is more challenging, and expensive, is fixing the existing car-oriented design. "It's easy to throw in a sidewalk or a crosswalk. It's totally different to think about making it a friendly, walkable place," said Jessica Millman, Maryland director of the Coalition for Smarter Growth.

One possibility is a program in Spotsylvania aimed at filling in the missing links between sidewalks. When Goss arrived from Florida nearly three years ago, the county often allowed builders to skip the sidewalks.

Now, developers that choose not to lay sidewalks must pay into a fund that covers the cost of connecting critical areas throughout the county, such as linking schools with older subdivisions where the developers are long gone. Neighborhoods in Charles were designed with sidewalks that start and stop at subdivision entrances. The planned community of St. Charles has trails for walkers and bikers within its individual villages, but the paths are not tied to each other or the St. Charles Towne Center Mall.

As the county grows, developers are starting to link new projects with older ones. A planned sidewalk and footbridge will make it possible to walk from Waldorf's movie theater to a new complex of six restaurants, said Craig Renner, a spokesman for American Community Properties Trust, the developer of St. Charles.

Still, Renner said, Route 301 remains a barrier to connecting neighborhoods separated by the state highway.

A study by the Coalition for Smarter Growth last year named Spotsylvania and Charles the Washington-Baltimore area's two most dangerous counties in which to walk.

Larger counties and cities had more fatal accidents involving pedestrians in 2002 and 2003. The report found that the District and Montgomery County, for instance, each had 25 deaths during the same period that Spotsylvania recorded four and Charles six.

But as a percentage of the walking population, the numbers are troubling to Kevin McCarty of the Surface Transportation Policy Project, a co-author of the danger index.

"You don't have a lot of people walking," he said, "and you still have people being killed at a higher rate."

Charles officials are not alarmed by the ranking, they say, because small numbers can produce dramatically different results from one year to the next.

"I don't think we are anywhere near emergency level, but we recognize we have issues," said Umling, the planning director. Maryland transportation officials said that until Charles decides that sidewalks are a priority for Route 301, the State Highway Administration will discourage people from walking and crossing there.

"We don't want people to start on one side, get halfway across and be unsure if they have some place to get to on the other side," said David Buck, a spokesman for the highway administration.

Poised on the edge of a grassy median on Route 301, Gordon Thurston turns his head with the rush-hour rhythm as he waits for an opening in the two lanes of traffic. The lights are timed for cars, not people, so Thurston picks a spot in the middle. When the cars begin to back up, he knows the light is about to change, and he's off.

"It's unbelievable," said Thurston, who walks the half-mile from his home in White Plains to work at Jimmie's Cut Rate Liquor.

"Just one mistake, and that's it."

Vehicles jam northbound lanes of Route 301 in Waldorf, where residents and shoppers must depend on their wheels to get to most places.Hoping to go shopping, William Lee makes a dash across Route 301 in Waldorf, where for four miles there are no crosswalks, sidewalks or traffic lights with pedestrian signals.