Statistics show that 69 million annual vehicle breakdowns occur in the United States. Although this number is largely composed of passenger cars, heavy-duty vehicles like refrigerated trucks and tractor units are no exception. When a large, heavy vehicle like a tractor unit breaks down, hiring heavy-duty towing services becomes necessary. Read on to discover more about heavy-duty towing and what it entails. Heavy-Duty Towing Explained Heavy-duty towing involves large, oversized vehicles like school buses, motorhomes, tractor-trailers, semis, and garbage trucks.