Commercial truck accidents can be more dangerous than car and light truck accidents for several reasons. One is simply that these vehicles are so much larger and heavier than passenger vehicles that they tend to do significantly more damage. Another is that commercial trucks are typically carrying materials, which may range from heavy objects that can break loose and cause serious injuries and damage to vehicles to toxic chemicals that can contaminate an area and shut down a roadway.
Large truck accidents can also be more serious because of the momentum with which the truck collides with another vehicle. A fully loaded semi truck may weigh up to 80,000 pounds, meaning that it takes longer to reduce speed or stop the vehicle.