Most anyone who’s driven to a trailhead in a national forest has encountered the phenomenon of washboard roads. And the even mildly curious among them have asked: What gives?
Scientists have come up with an answer. Basically, people are driving too fast on those roads. Mathew Preusch of the Oregonian detailed a study in a blog post today. Says University of Toronto physicist, Stephen Morris, one of the researchers involved:
“We built lab experiments in which we replaced the wheel with a suspension rolling over a road with a simple inclined plow blade, without any spring or suspension, dragging over a bed of dry sand. Ripples appear when the plow moves above a certain threshold speed.”