It depends on the cause of the accident.
When Michael runs into Meredith with his car, Michael is at fault and Meredith will bring a personal injury lawsuit against him. But if Michael is driving a semi-truck when a piece of cargo falls off and hits Meredith’s car, the number of different parties potentially responsible for Meredith’s injuries multiplies.
Because each of these parties must be identified, commercial truck accidents are more complicated to pursue than car accidents. To take a simple case, the truck and trailer components of a semi-truck are often owned separately and by corporate entities, not individuals. This results in potentially two separate companies being responsible for your injuries.
Furthermore, you must sue the corporate entities themselves, not someone at the company, and figuring out who and what company or corporation to sue can sometimes be difficult, especially if the trucking company is a nationwide company.