With the number of environmental accessibility standards currently in play — ramp slopes and doorway widths, for example — it may come as a surprise that such a standard doesn’t yet exist for American sidewalks.

Jonathan Pearlman, Ph.D., is the associate director of engineering in the Human Engineering Research Labs, VA Pittsburgh Healthcare System. He says, “Currently there are no set standards for sidewalk roughness that is relevant to wheelchair use over the sidewalk. It’s a big area of my research right now, to help develop those standards so we can improve that issue.”

That lack of a resource means architects and builders have no official guidelines to refer to. But that’s changing. And as with any evolution, understanding that there’s a problem is step one.

Pearlman is involved in a three-year study that he says will try to understand the impact of surface roughness on wheelchair users.

“It’s actually the Access Board that is funding our study,” he says. “They have accessibility guidelines for pathways, and the accessibility standards are related to the slope, the running and cross slope. It’s related to level changes, so anything greater than a quarter-inch is the threshold. But it’s not getting down into the weeds about what does that really mean? Because it only says a quarter-inch change in level. It doesn’t say the frequency that that quarter-inch change could occur; it just says that if there’s more than a quarterinch bump, then that could be out of compliance.”

Pearlman adds that the Access Board knows “that surfaces should be stable, firm and slip resistant, but they don’t talk about smoothness of it, so it’s become a pretty big issue. Because we know wheelchair users are not satisfied with sidewalks.”