There are several reasons why semi-truck crashes tend to involve multiple vehicles.
Size – Semis are much bigger than the standard car on the road today. To put it into perspective, the typical car weight is about 4,000 pounds. By contrast, the average semi weighs up to 80,000 pounds and in some places semis are permitted to weigh more.
Speed – Actually, it’s not necessarily that semis drive faster than other cars; it’s the fact that it takes them much longer to slow down. By the time a trucker brings their truck to a complete stop, it might have crashed into several vehicles. It’s a bit like a battering ram barreling down the highway.
Deadlines – Truck drivers often feel pressure from their companies to make their shipments on tight deadlines. This can cause some drivers to ignore the hours of service regulations, which causes a dangerous drowsy driving situation.