I always wonder why semi-trailer trucks are also called Fifth wheel vehicles while I don’t see any fifth wheel rolling, LOL! You may call me stupid but that is true! It was only recently that I realized that the fifth wheel being referred to in such vehicles is the device used to connect a truck tractor and the semitrailer van and to permit articulation between the two. This also makes a fifth wheel vehicle different from an ordinary auto. Thus, an ordinary auto-insurance is not applicable to fifth wheel vehicles. Instead a specialized 5th wheel insurance is should be applied for such vehicles.