Tractor-trailers have higher fatal crash rates per mile than passenger vehicles. The main problem is the vulnerability of people traveling in smaller vehicles. Trucks often weigh 20-30 times as much as passenger cars.
Truck braking capability is a safety problem.
4 Other issues involve the drivers of large trucks, who are allowed to drive up to 16 hours per day and 70 hours in 5 days. Large trucks accounted for 4 percent of registered vehicles and 8 percent of miles driven in 1999. They were involved in 12 percent of all passenger vehicle occupant deaths in 1999 and 23 percent of passenger vehicle occupant deaths in multiple-vehicle crashes. Eighty-two percent of fatal large truck crashes in 1999 involved 2 or more vehicles. This compares with 47 percent of fatal passenger vehicle crashes.