A tractor-trailer engulfed in flames slowed traffic just before Pinole Valley Road at about 2:20 a.m., the CHP said.
A Sig Alert closing all lanes of traffic was issued shortly after 2:30 a.m. The far left lane of traffic reopened at about 3:15 a.m., according to the CHP.
All lanes of traffic reopened at about 4:25 a.m., the CHP said.
The cause of the collision remains under investigation.
