Is it a car? Is it a tram? No, it's an automated taxi service. The technical challenge of building Cabtrack were, apparently, more easily overcome than public scepticism, despite the best efforts of this quirky promo. Then and now, the unmanned taxi feels like the stuff of sci-fi - the Docklands Light Railway may be the nearest we've come to realising the concept.
Cabtrack was one of several prototype Personal Rapid Transit systems to be floated globally in the 1960s and 70s. The Royal Aircraft Establishment was commissioned by The Ministry of Transport to research the project thoroughly, investing in the test-track and one-fifth-scale model shown in the film, though all development stopped in 1972.