A brush fire shut down westbound Interstate 8 in the Jacumba area on Monday.
A Sig Alert started around 4:45 p.m. for I-8 at Carrizo Gorge Road after heavy smoke from the fire clouded the freeway.
As of 6:20 p.m., the California Highway Patrol said one lane was reopened. The entire westbound side of the freeway was cleared within the next hour.
Firefighters were able to contain the fire after it grew to 40 acres, according to Cal Fire.
No structures were threatened, and no injuries were reported.