The majority of semi-truck accidents can be credited to two main reasons - long stopping distances and the total weight of the vehicles involved. Big trucks, on average, need almost twice the braking length of cars if they need to stop while going at the same speed as a passenger car.
And when you consider vehicle weights, there is no comparison between the two. Most cars average about 5000 pounds or less in weight. Now consider a fully stocked semi-truck. They can easily weigh up to 80,000 pounds. So if an accident occurs between a car and a semi-truck, there is no way that the smaller vehicle will come out of it unscathed.
﻿Speeding is another common cause of accidents. For example, trucks often cause accidents by going around curves way too fast and cross the lanes, lose the loads they are hauling, etc. Other truck accidents can be credited to things such as mechanical failure, following too closely, defective brakes or other equipment, driver fatigue, DUI, improper loading, and poor vehicle maintenance.