Sep 28 2006
The streets of America were never paved with gold, but now some of its sidewalks are made of rubber.
Dozens of communities have installed rubber because it coexists with tree roots more easily than concrete. The latter buckles as roots grow under it; rubber merely bends. As a result, trees are spared from root damage, municipalities from trip-and-fall lawsuits.
"A rubber sidewalk? It sounds preposterous," admits Richard Valeriano, senior sidewalk inspector for the city of Santa Monica, Calif., and father of the rubber sidewalk.
The idea came to him in a dream after a day of staring down at yard after yard of pavement cracked by ficus tree roots.
That night, in his sleep, he saw concrete pavement rippling, flowing, undulating. But he didn't know what it meant until he noticed his health club installing a rubber indoor sports floor. "That," he says, "is when the penny dropped."
The city worked with the sports floor manufacturer on a rubber sidewalk prototype made from recycled tires. After the modular, pre-molded panels passed test-exposure to hazards such as rollerblades, bike stands and high heels, the city began laying rubber in 2001.
Rubbersidewalks of Gardena, Calif., began commercial production in 2004. Lindsay Smith, the company's president, says more than 60 municipalities have ordered panels.
She says that unlike poured concrete, the rubber panels have spaces between them, so rainwater can trickle down more easily to the roots, making them less likely to press up in search of moisture. The panels are removable, so arborists can trim and redirect roots without tearing up the sidewalk. They also help recycle the nation's vast supply of old tires.
Rubber sidewalks are soft — not bouncy, really, but with more give than concrete. "You can drop a glass on it, and it won't break," Valeriano says. In sales demonstrations, Smith does just that.
The sidewalks on Sutton Manor Road in New Rochelle, N.Y., are so wracked by linden tree roots that pedestrians use the street, says Terry Gargan, a semi-retired maritime lawyer. "I look at the sidewalks on this street, and I see 20 potential lawsuits."
But not in front of his house, where the city installed a slate-colored rubber sidewalk. He says people notice the difference only when they step on it and feel a certain spring. "They come up and ring the bell: 'What's the story?' "
Earlier this year, Washington D.C., spent about $60,000 to install 4,000 square feet of rubber sidewalks on several leafy blocks in the city's Northeast section.
On Sept. 13, the Boston City Council voted to study installing such sidewalks there.
Council member Rob Consalvo says some constituents in his largely suburban district were demanding the removal of trees whose volcanic roots effectively closed sidewalks to baby strollers, wheelchairs and the elderly.
Unless the price of concrete explodes, however, rubber may remain little more than a niche surface for use around large trees. Even in Santa Monica, rubber sidewalks have been installed at only 80 addresses.
It's expensive — two to three times the cost of concrete, partly because of the cost of shipment from Southern California.
Smith says that will change in the East when her company opens a plant next year in Lockport, N.Y.
She also says that the value of a large shade tree should be considered in the price of a rubber sidewalk, along with the cost (and noise) of having to tear up and replace buckled concrete every two or three years.
For kids, there's a downside: You can't immortalize yourself by stick-drawing your initials in wet rubber. An upside: fewer skinned knees.
Valeriano predicts that rubber will spread gradually across the streetscape. "I could never have thought of that if I tried," he says. "It had to come in a dream."