A Driving Van Trailer (DVT) is a purpose-built control car railway vehicle that allows the driver to operate with a locomotive in push-pull formation from the opposite end of a train. Trains operating with a DVT consequently do not need the locomotive to be moved around to the other end of the train at terminal stations. Unlike many other control cars, DVTs resemble locomotives (specifically Class 91) and thus when the train is operating in push mode, it does not appear to be travelling backwards. The vehicles do not have any passenger accommodation due to health and safety rules in place at the time of construction that prohibited passengers in the leading carriages of trains that run faster than 100 miles per hour (160 km/h). Historically, it was believed that a train would be unstable at high speeds unless pulled from the front but extensive testing, and the experience of high speed trains with central power cars such as the British Rail APT and the Eurostar, have altered this view.