Sign; Standard MOT road warning sign, tram Pinch, red warning triangle, London, circa 1936

This sign is a standard safety road sign of a style introduced by the Ministry of Transport around 1935. Such signs were used where tram tracks converged with the side of the road, so that a bus or car would be squeezed onto the kerb if it drove alongside a tram. The signs also acted as a warning to cyclists since tram rails could present a slipping hazard.This kind of problem was common in London, where the streets were often too narrow to allow trams and other road vehicles to run side by side. By the early 1950s, trams were being withdrawn from service, so this sign was probably removed at about that time.