Pedestrians in a section of the nation's capital may notice a new bounce in their step as Washington experiments with rubber sidewalks.

In one of the biggest tests in the country, Washington recently installed rubber sidewalks around trees on a portion of Rhode Island Avenue, The Washington Post said.

The cost was $60,000, roughly three times more than if it had been concrete. But the walkways are said to last about 14 years around tree roots, nearly three times longer than concrete ones, the Post reports.

This is good for the trees, says John Thomas, the city's chief arborist.

Concrete suffocates tree roots, which then grow upward to fight for air and water, he says. The roots break the concrete, which pedestrians can trip over.

By contrast, rubber sidewalk panels have quarter-inch spaces between them that let air and water through, so tree roots grow downward, as they would in nature.

The sidewalks are also easier on people's knees.

The walkways are made of ground recycled tires molded into squares. One car tire can make 1 square foot of rubber pavement, the manufacturer, Rubbersidewalks Inc. of Gardena, Calif., said.

Copyright 2006 by United Press International