The fire was reported shortly after 3 p.m. behind a Shell gas station. Passing drivers could see smoke and flames from the I-5.
Firefighters initially requested support from two helicopters, but they canceled the request for one a short time later.
No structures were threatened by the flames, according to the San Diego Fire-Rescue Department.
Another small fire was reported just after 3 p.m. at Interstate 805 and state Route 15. Both sides of I-805 were closed for a short time until firefighters got control of the blaze. By 3:40 p.m., at least one lane of the freeway had been reopened.
This story will be updated as more information becomes available.