VALLEJO (CBS SF) — All lanes of Interstate 80 are reopened after being closed at Magazine Street in Vallejo due to police activity, according to the CHP.

A severe traffic alert was issued for the area around 4 p.m. and lasted for hours during peak commute hours, causing standstill traffic for many on the Carquinez Bridge.

READ MORE: Napa Valley Looks to Restaurant Week to Help Jump-Start Economic Comeback

All lanes were closed in both directions and traffic was being diverted off to Magazine Street.

The police investigation was happening at the Magazine Street overpass near Lincoln Road.

READ MORE: Wind-Whipped Wildfire in Big Sur Shuts Hwy 1, Forces Evacuations

Motorists were advised to expect delays and to use alternate routes to avoid the area.

All lanes were reopened at 5:55 p.m., the CHP said. The incident lasted around two hours and 40 minutes.

Authorities did not specify the cause of the police activity nor the circumstances surrounding the investigation as of Monday evening.

MORE NEWS: Curry Hits Winning Jumper, Warriors Beat Rockets 105-103