A two-vehicle crash on the Los Osos Valley Road overpass snarled traffic on Highway 101 through San Luis Obispo on Monday.
It happened at about 4:30 p.m.
The northbound offramp was shut down as a result of the crash, causing traffic to back up on northbound Highway 101 as well as nearby surface streets.
According to police at the scene, one of the two drivers involved in the crash was taken to the hospital.
A third driver, who police say stopped to help, was also arrested on suspicion of DUI.
