In 1946, his father bought Central Cartage Company, which would later become Central Transport, and Moroun started working with him. During college, Matty regularly commuted between the University of Notre Dame in South Bend, Indiana, and Detroit to help run the family business. He graduated in 1949 with a bachelor's degree in chemistry and biology. He aspired to become a doctor, but ultimately went back to Detroit to work at the family's service station. He also cleaned and serviced buses for a living. By the middle of the 1950s, he was responsible for managing most of his family's trucking business.