Vehicle insurance purchased for cars, trucks, motorcycles, and other road vehicles. Its primary use is to provide financial protection against physical damage. Business auto liability insurance helps cover the financial responsibility if you or an employee is at fault in an accident and people are injured or property is damaged. A minimum amount of commercial auto liability insurance (or proof of financial responsibility) is required in most states. Some states also require underinsured motorist and uninsured motorist coverage to protect you when the at-fault driver is unable to pay the total cost. Collision or comprehensive insurance is often optional.