Comparative negligence makes it possible for an incident to have multiple at fault parties. Each party contributed to the accident to certain amount, and insurance companies will then negotiate the payments to be allocated accordingly. There are two methods for working these costs out: Pure Comparative Negligence, and Modified Comparative Negligence.
Under Pure Comparative Negligence, the claimant may receive compensation up to the full amount of the damages minus the amount of the own negligence. In this way, if the claimant were only found to be 25% at fault, then they would be entitled to 75% compensation for the insurance company. This method shares the liability equally, according to the amount of blame is shared by each person.
The more common variety, Modified Comparative Negligence, relies on the percentages of fault, and may not pay out at all if the fault is greater than a certain percentage, usually 49%. This type of comparative fault works out to the benefit of insurance companies, but does not work well in settling claims where more than a single party shares the fault. Modified Comparative Negligence makes it possible for claims to go unpaid based on a participating guilt.
As for deciding who is at fault, the first course of action is to check the police reports. If there is a dispute over the items listed in the report, then a reasonable effort must be made to contact witnesses or gather other information. In some serious cases, the decision of blame may end up in a courtroom for a decision by jury.