Philadelphia will soon use a new tool to separate cyclists from moving cars: other cars.

For about half a mile on Ryan Avenue, between Lexington and Rowland Avenues in the Mayfair neighborhood, parallel parking space will be moved about 14 feet from the curb to make room for a bike lane in each direction.

When the change is completed by August, city officials said, cyclists in the area will travel adjacent to the curb, separated from car traffic by parked cars and a four-foot buffer zone marked with flexible posts.

Placing parked cars between bike lanes and traffic is done elsewhere, such as New York City, but hasn't been tried in Philadelphia. Ryan Avenue, which already has bike lanes and is pedestrian-friendly, is likely to be a model for other roads in the city.

"The next step would be to go to areas where perhaps there's more demand for cyclists," said Jeannette Brugger, pedestrian and bicycle coordinator for the deputy managing director's office of transportation and infrastructure systems. "These types of facilities are very effective in areas where there's a lot of cyclists using them."

Cycling advocates have long sought protected bike lanes, which use physical dividers, not just painted lines, to mark portions of a road reserved for bicycles. They are safer, experts said, and offer an added sense of security for people who might otherwise feel unsafe bicycling with nothing between them and moving cars. Officials said the lanes also would discourage bikers from using sidewalks and would keep delivery trucks from stopping in bike lanes.

"Just adding that one-mile stretch of bike lanes is not going to create a huge impact, but it is the beginning of a network," said John Boyle, research director for the Bicycle Coalition of Greater Philadelphia.

The portion of Ryan Avenue being converted passes over Sandy Run Creek. The work is expected to begin in late June or early July.

Using parked cars as the barrier between traffic and bikers won't work everywhere because of Philadelphia's narrow streets, advocates said, but there are places where it's an ideal option. The Bicycle Coalition is eyeing John F. Kennedy Boulevard between City Hall and 30th Street Station as a street wide enough and heavily traveled enough to warrant pushing parking away from the curb to make room for bikes, said Bob Previdi, the organization's policy coordinator.

In March the city received a $300,000 federal Transportation Alternatives Program grant for 30 miles of protected bike lanes in the city over the next four years. To keep costs low, the city is making bike-lane improvements in concert with scheduled road resurfacing.

"The only extra cost is the flexible delineator posts, some additional signage," Brugger said.

The city does have a list of locations that are candidates for parking-protected bike lanes but isn't publicizing it until more community outreach is done, Brugger said.

Protected bike lanes that use just the flexible posts to separate traffic from cyclists exist on the Walnut Street Bridge, and they are being created on the Fifth Street Underpass and on Tyson Avenue between Torresdale and Frankford Avenues, Boyle said.