Most cases resolve without going to trial. The cases that go to trial go there for a number of reasons. It could be that the liability is disputed. You've got people disagreeing on how the action happened. You also have disputes as to the injury. Generally, defendants contest injuries of people that claim to be injured. They have doctors that'll say, "I don't think that accident caused that injury." There are a lot of reasons why you should, or could go to trial. And a lot of reasons why the case settles, because you avoid the uncertainty of a trial. And generally, the expectation is cases settle.
