The Allamuchy Fire Department responded to the eastbound side of the highway near milepost 18 as the fully involved blaze was reported around 6 p.m., the company said.
The department extinguished the smoky blaze after stretching a hand line to the vehicle while other crew members provided traffic blocks and additional support, authorities said.
All crews had cleared the scene about an hour later, the department said.
The cause of the fire was not immediately clear.
Click here to follow Daily Voice North Hunterdon and receive free news updates.