There are two main ways truck accidents differ from average car accidents.
Practical differences: Tractor-trailers and other commercial vehicles are larger than cars, with different parts, tipping points, and abilities (like jack-knifing). They also tend to carry dangerous materials. All of these factors make truck accidents far more likely to cause catastrophic injuries than car accidents.
Legal differences: An accident with another car usually only involves drivers, passengers, and insurance companies. A crash with a commercial truck potentially involves drivers, passengers, insurance companies, contractors, owners, and businesses. This complicates personal injury cases and may involve other factors, like intimidation from corporate entities that don’t want to pay out a fair settlement.