The fire broke out shortly after 11 a.m. Monday, when the truck overturned on the Route 90 on-ramp to Route 130 in Pennsauken.
Video shows the truck burning just a few hundred feet from a neighborhood. The smoke could be seen 5 miles away in downtown Philadelphia.
Firefighters are dousing the blaze with foam from across the highway.
Nearby homes are being evacuated as a precaution, and traffic is being diverted from the area.
Authorities say the driver was able to get out of the vehicle.
It's not clear what caused the truck to overturn.
The Associated Press contributed to this story.