SAN FRANCISCO (CBS SF) — A traffic alert was issued early Thursday evening after two separate injury accidents slowed westbound traffic on the Bay Bridge.

The first accident happened on westbound I-80 just west of the toll plaza at about 5:15 p.m. The injury accident blocked the three left lanes. Lanes remained closed for about 45 minutes, reopening at around 6 p.m.

The second crash occurred about 15 minutes later on westbound I-80 just west of Treasure Island. That injury accident involving an overturned vehicle shut down the two right lanes.

Motorists are advised to expect delays and to use alternate routes. There is no estimated time of opening.