Road tax is a tax levied on vehicles to permit their use on public roads. It has undergone two major changes as a result of the increase in terraplane use. Firstly, private terraplanes are charged road tax at a very low rate depending on their use of roads. Early in their use, it was found that many pilots would avoid paying road tax by attempting to avoid roads entirely, which was frequently dangerous, so road tax was reduced in order to prevent this. It was also noted that the wear and tear of an air cushion vehicle on a road was much lower than that of a wheeled vehicle, and the maintenance of roads became less important because of the decline in the use of wheeled vehicles.
Secondly, since there are still commercial wheeled vehicles, road tax is still charged for wheeled vehicles used for commercial purposes such as lorries and vans. However, this is also lower in relative terms than it used to be.