From the longer Wikipedia page [1]
The West London Tram (also known as West London Transit) was a proposed on-street light rail line that was to run along the Uxbridge Road (A4020) corridor in West London, England. The scheme was promoted by Transport for London (TfL). It was postponed indefinitely on 2 August 2007 as opposed then by the councils of all three bisected London Boroughs.
The tram route was planned to run between Uxbridge and Shepherd's Bush, serving Hayes (north), Hillingdon, Southall, Hanwell, West Ealing, Ealing and Acton en route, and would have replaced three equivalent London Buses routes. The proposed route is same route of the number 7 tram (London's Tram route 7) from about 1905 until 1951.