A road train, also known as a land train or long combination vehicle (LCV) is a semi-truck used to move road freight more efficiently than single-trailer semi-trucks. It consists of one semi-trailer or more connected together with or without a tractor.[1] It typically has to be at least three trailers and one tractor. Road trains are often used in areas where other forms of heavy transport (freight train, cargo aircraft, container ship) are not feasible or practical.