All lanes have reopened on northbound state Highway 29 near American Canyon after a big-rig loaded with mail overturned early Thursday morning, according to the California Highway Patrol.
The crash was reported around 4:30 a.m. The 55-foot U.S. Postal Service trailer landed on its side, spilling mail on the highway at South Kelly Road and prompting the closure of both lanes, according to the CHP.
CHP Officer Marc Renspurger said the incident is under investigation but the mail carrier driver might have been sleepy.
An employee from the Napa Post Office responded to collect the mail that fell out of the trailer, Renspurger said.
The northbound lanes of the highway reopened at 9:02 a.m. Traffic lights, however, were not working and cars were backed up for miles.