Why Are Large Truck Accidents So Often Fatal?


Large trucks—also known as semi-trucks, semi-tractor trailers, “semis,” “big rigs,” and “18 wheelers,”—represent just 1% of registered vehicles. But they are involved in 14% of fatal crashes.1

The truck’s mass is the main reason large truck accidents are so deadly. These vehicles have weights ranging from a minimum of 10,000 pounds to 80,000 when fully loaded.2 For comparison, the average male elephant, the largest land animal, has an average weight of only 11,000 pounds.3 The average passenger car weighs just 4,000 pounds.4 An accident with one of these fully loaded large trucks can be like colliding with 20 cars at once!

Speed is another major reason that large truck accidents are more fatal. Speed–even if the truck is traveling at the speed limit–multiplies by factors their destructive force. The greater the speed, the greater the forces involved, as we all learned in high school (mass (kg) x acceleration (m/s) = force (newtons)).  Some examples below illustrate the exponential increase in force when large trucks are driving at higher rates of speed.

For one car at 4,000 pounds traveling at 20 mph has 16,217 newtons of force.

      1,814 kg * 8.94 m/s = 16,217 newtons

If you increase the speed to 60 mph, the result is 48,651 newtons of force.

      1,814 kg * 26.82 m/s = 48,651 newtons

If you add the mass of a large truck at 80,000 pounds traveling at 60 mph, the result is 973,217 newtons of force.

      36,287 kg * 26.82 m/s = 973,217 newtons

The greater mass of large commercial vehicle yields tremendous destructive force—and results in much more serious injuries and more fatalities. Passenger cars and light trucks were not designed to withstand collisions involving this much force. This also explains why more of the fatalities in these accidents occur in cars and light trucks: 70% were in cars and light trucks and only 20% in large trucks.6 

If you or a loved one are involved in accident with an 18 wheeler or other large commercial vehicle, contact an attorney as soon as possible. The investigation, fault determination, and other processes in these accidents are significantly different and more complex than regular passenger vehicle accidents. The investigation must start immediately after the crash so relevant evidence is preserved.  Moreover, you will need an attorney to fight on your behalf with the trucking company’s insurer and/or attorneys to obtain full compensation for you or your loved one’s injuries and losses. Contact Wyly and Cook, PLLC, for a free consultation at 713-236-8330 as soon as possible if you are involved in an accident with an 18 wheeler, semi-truck, or other large commercial vehicle. 


1 Federal Motor Carrier Safety Association, Pocket Guide for 2020.

2 https://policyadvice.net/insurance/insights/truck-accident-statistics/. 

3 https://www.elephant-world.com/elephant-weight/.

4 https://mechanicbase.com/cars/car-weight/.

5 Deaths in large truck crashes by road type, 2019, https://www.iihs.org/topics/fatality-statistics/detail/large-trucks.

6 Federal Motor Carrier Safety Association, Pocket Guide for 2020.


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Wyly & Cook, PLLC

The team at Wyly & Cook, PLLC brings a diverse body of trial and litigation experience to the table, putting us in a unique position to help clients with a wide range of legal issues.
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