When I visit northern Minnesota, I always encounter a road that in midsummer becomes classically "washboard." The county sends out a road grader to smooth it and give it a new crown, and a few weeks later it's a washboard again.
Minnesotastan looked up the physics of why this happens. The explanation includes a video that led to the discussion of the word "widdershins" in the comments. Link
(Image credit: David C. Mays)