NEW BRUNSWICK, NJ—Ahmed Ewida, manager of the Just Delicious truck, shakes his head. He’s trying to keep a business afloat despite having new gas and electricity expenses and a customer base that’s been sliced nearly in half.

Samir Alkilani, owner of Mr. C’s grease truck, can do nothing but watch as group after group of students bypass his truck in favor of using their meal swipes at nearby Neilson dining hall, where they can eat as much as they want and then take more food to go.