Traffic accidents involving large trucks or 18-wheelers are significantly more dangerous and destructive than those involving only smaller vehicles. The sheer size and weight of these large vehicles often leads to more severe outcomes when collisions occur.

The Federal Motor Carrier Safety Administration (FMCSA) provides data that illustrates this point. According to its latest reports, out of the total traffic fatalities in 2019, around 5,000 involved large trucks. These figures can be compared with the total traffic fatalities for that year, around 36,000, meaning approximately 14% of all traffic fatalities involved a large truck or 18-wheeler, despite these vehicles comprising a much smaller fraction of total vehicles on the road.

The weight of a standard passenger vehicle ranges from 3,000 to 4,000 pounds. In contrast, an 18-wheeler can weigh up to 80,000 pounds when fully loaded. This weight disparity makes it more difficult for trucks to maneuver quickly or stop in emergencies, often leading to more forceful impacts and consequently, more severe injuries or fatalities.

Moreover, the size and height of large trucks and 18-wheelers can lead to "underride" accidents, a particularly deadly type of accident where a smaller vehicle slides underneath the truck. Even with underride guards, smaller vehicles often suffer extensive damage, particularly to the passenger compartment, in these accidents.

Another factor contributing to the severity of truck-related accidents is the load they carry. Trucks often transport hazardous materials, which, when involved in a collision, can cause fires, explosions, or the release of toxic substances. This risk is not as prevalent in accidents involving only smaller vehicles.

The nature of trucking—long hours on the road, often under pressure to deliver loads within tight schedules—also plays a role in the danger associated with large truck accidents. Driver fatigue is a leading cause of truck accidents, as per the FMCSA data. Tired drivers are less able to react quickly in unexpected situations and more likely to make errors leading to accidents.

Finally, the damage to infrastructure can be much greater in accidents involving large trucks. Due to the weight and momentum of these vehicles, they can cause substantial damage to roadways, barriers, bridges, and buildings that may be near a crash site. This additional damage can create secondary accidents, putting even more people at risk.

Accidents involving large trucks and 18-wheelers are more dangerous than those that do not involve these vehicles for several reasons. Their size and weight make collisions more destructive, and their handling characteristics can contribute to the severity and frequency of accidents. Furthermore, the nature of trucking operations often adds additional risk factors like driver fatigue and hazardous materials transportation. All these factors result in higher rates of severe injury and death in accidents involving large trucks compared to those involving only smaller vehicles.