chatter bump
n.— «One of her most unusual assignments was to build a road with all the wrong bankings. She created a four-mile nightmare of incorrectly canted curves, chatter bumps, potholes and a hundred other hazards found on rural highways. It’s [sic] use was to test the handling qualities of cars under the worst possible conditions.» —“Hoped Fashion To Be Her Field, But She Designs Roads” by David Chute in Highland, Mich. Vidette-Messenger (Valparaiso, Ind.) July 30, 1969. (source: Double-Tongued Dictionary)
Further reading
Amid court-ordered busing in the 1970s, a middle-school teacher tried to distract her nervous students on the first day of class with this strange assignment: find a monarch caterpillar. The result? A memorable lesson in the miracle of metamorphosis...
She sells seashells by the seashore. Who is the she in this tongue twister? Some claim it’s the young Mary Anning, who went on to become a famous 19th-century British paleontologist. Dubious perhaps, but the story of her rise from seaside...