Ex-NFL head coach and current Wisconsin football adviser Jack Del Rio was busted for driving while intoxicated in Madison ... after cops say his car drove into a street sign and fence.
61-year-old Del Rio -- who joined the Badgers' staff under Luke Fickell in August -- was arrested after officers were called to the scene around 12:35 AM on Friday.
Madison PD tells TMZ Sports -- a vehicle hit a street marker, broke a fence and came to rest in a yard .