courtesy crash
n.— «The other problem is that people in the right lane of westbound U.S. 10 are allowing people in the businesses to turn out into the left lane of the road. Oncoming drivers in the left lane don’t see them entering the road and traffic accidents are the result. The accidents are commonly called “courtesy crashes.”» —“A matter of timing and courtesy?” by Brian Mulherin Daily News (Ludington, Michigan) June 14, 2007. (source: Double-Tongued Dictionary)