A carrier operates trucks and often times is an owner-operator who only schedules shipments through a broker and serves only a few routes. A broker has a huge network of car carriers serving the whole country. In most cases, a broker can give you a lower rate since they have multiple carriers competing to transport your vehicle. Brokers also verify the USDOT authority, federal licenses and cargo insurance of the carrier company transporting your vehicle. A broker is an expert in the industry and will guarantee that your car is shipped by a legitimate carrier. It can be difficult to verify these things on your own.