Four high-speed motorists who disrupted traffic on the Bay Bridge with a display of show-off driving and “doughnuts” found their sideshow come to an unexpected end after a stalled motorist captured the display on a cell phone camera and alerted the California Highway Patrol, officials said Monday.

The incident began around 3:30 p.m. Sunday when Bay Bridge motorists observed two Ford Mustangs — one black and one white — a Chevrolet Camaro and an unidentified maroon car speeding westbound on the bridge at up to 90 mph, weaving through traffic.