This article is provided as a public service by the Geophysical Institute, University of Alaska Fairbanks, in cooperation with the UAF research community. Larry Gedney is a seismologist at the Institute.
Washboard roads are a bane to travelers worldwide.
This includes, of course, Alaska, where the options for getting away from it all would be limited indeed if gravel roads are excluded from one's itinerary. Corrugations that produce washboard roads are not limited to those with sand or gravel surfaces, but are also found in asphalt pavements and even in railroad tracks, although on a less severe scale. It would seem that such a common phenomenon should be readily understood and explainable, but the fact is that the process which produces them was a subject of controversy among engineers for many years. One of the most popular theories was that a tire, even as it rolls, pushes material ahead of it in a heap. Once the pile reaches a certain size, the tire rolls over it and starts the process again.