The incident happened around 5:30 a.m. in Upper Macungie Twp., Lehigh County.
The tractor trailer driver told 69News that a tire on the trailer blew, which caused a second tire to catch fire. He was hauling shredded paper.
He said he was able to drop the trailer and move the cab away from the fire.
The truck was on the shoulder of I-78 west of Route 100, at mile marker 49.4.
There were no injuries.