The California Highway Patrol responded to an injury traffic accident at the top of the Cuesta Grade on Friday at 5:51 p.m.
A large truck, possibly a trash truck, had crashed, rolled over and was blocking all the northbound lanes. Another vehicle was involved, according to the CHP San Luis Obispo office.
The accident had caused rush-hour traffic to back up on the Cuesta Grade.
Meanwhile, a weather-related power outage at 6:48 p.m. has left 5,400 people in Arroyo Grande without electricity Friday night. The outage knocked out power at the high school, where a game between Atascadero and Arroyo Grande was about to begin.
The game was postponed to 1 p.m. Saturday.
Crews are on the way to make repairs, said Blair Jones, PG&E spokesman.
No estimate of when power will be restored is available.