It was in 1951 the decision was taken to develop a lightweight vehicle with the ability to seat 64 passengers, an initial estimate of 2,000 vehicles being suggested. Several protoypes appeared over the next few years and testing of the buses took place with development being carried out by a range of companies. It was not until the early sixties that the buses were seen on the streets of London in any quantity and by now a decision had been made to concentrate the future development of buses on one-person operated vehicles. No further Routemasters were built after 1968 although due to maintenance, refurbishment and deregulation they are still seen not only in the capital, but also in many locations throughout the UK and overseas.