Motorcycle and truck accident lawsuits are usually also based on the concept of negligence, wherein the plaintiff must prove the four elements of duty, breach, causation, and damages. Generally, motorcycles must follow the same rules of the road as applied to other vehicles. However, motorcycle operators are often subject to additional requirements, e.g. safety equipment and special licensing. If the motorcycle rider fails to comply with these requirements at the moment of the accident, he or she may be regarded as partially at fault. In such cases, comparative negligence principles will apply wherein the sum of damages will be calculated based on the amount of each partyâ€™s fault.