The Open Guide to London: the free London guide

Buses powered by overhead electric wires. Essentially a tram with no rails. These proliferated in London for a decade between the removal of the trams and the introduction of the diesel bus, since trams' overhead wires were easily adapted to use by the trolleybus.

Trolleybuses are relatively common abroad but are not a feature of British transport. However, they were considered for Cross River Transit and West London Transit, and may yet be used for East London Transit and Greenwich Waterfront Transit.