The call came in around 1:44 p.m. of smoke from a vehicle in the middle lane near Treasure Island, the California Highway Patrol said.
The CHP tweeted a photo of the sedan that caught fire and appeared to be connected to a motorhome.
You can see the engine completely burned.
Lanes reopened at 3:09 p.m.
No injuries were reported.
The fire happened during a normally busy afternoon commute back to the East Bay.
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