In an ordinary motor vehicle accident case, the plaintiff is generally the driver who believes that he or she was injured by the defendant, another driver. However, when the defendant driver is a professional driver or even just a person who was driving at that moment as part of his or her job duties, the case is likely to take on more complexity, because it is possible to bring the employer into the lawsuit along with the driver as defendants.
The legal doctrine that sometimes would allow an employer to be brought into the lawsuit is called Respondeat Superior, or vicarious liability. The idea behind the doctrine is that the employer may be held responsible for the wrongful acts of its agent. Now, this doctrine does not apply in every situation, just as intuition would lead one to believe that in some instances that would not be fair to the employer. Generally, the threshold question for whether it is allowable to bring the employer into the lawsuit is whether or not the driver was acting in the course of performing his or her job.
For example, if Defendant Driver Dane is driving and runs a red light while en route to deliver a package for Generic Parcel Company (GPC)* because he is trying to make a quota imposed by GPC, and Dane strikes your car injuring you, most likely, not only Dane himself, but also GPC may be named as defendants in the lawsuit. Conversely, if Dane is driving toward a delivery, and then decides he is going to participate in an illegal drag race before delivering the package, and while driving recklessly he strikes your car injuring you, then most likely GPC will be off the hook. The main difference is that GPC does not reasonably expect Dane to be engaging in drag racing, and so it should not be held liable for his recklessness. And of course, hopefully it makes sense that causing Dane to drive recklessly by imposing a quota is maybe a grounds to be sued (depending on how unreasonable the quota is), while having an employee randomly decide to drag race while on the clock is far less blameworthy.
So, the rule of thumb to remember is that if you have been injured in an automobile accident, and the driver of the other vehicle was driving in the course of his or her job, whether it be mail delivery, public transportation, taxis, or any other type of person who drives for a living, or even those who do not drive for a living but were driving for their employer at that moment, then your case might be different than you originally expected.
*In case anyone is wondering, Generic Parcel Company is a made up name, and if we happen to name any real business entity, it is purely by coincidence and we do not mean to insinuate that GPC has done any wrongful acts.