[10][page needed] The GW&GCJR connected London and the Midlands via High Wycombe and provided an alternative route to the Great Central Railway's (GCR's) main line through Aylesbury, Harrow and Wembley which shared its route with the Metropolitan Railway.

The London Passenger Transport Board's (LPTB's) 1935-40 New Works programme included the extension of the Central line to run alongside the Great Western Railway (GWR) tracks from North Acton to South Ruislip and the GW&GCJR tracks from there as far as Denham; the post-war introduction of the Metropolitan Green Belt caused the extension to be cut back to West Ruislip.

The additional tracks were constructed by the GWR on behalf of the LPTB and on 30 June 1947, the first section of the western extension opened from North Acton to Greenford.

Such a project would require a business case approved by TfL and the completion of signal upgrade work on the Metropolitan line.

The station's weekday off-peak service pattern is unusual in that it's served by trains at different frequencies in each direction.

The typical off-peak London Underground service on the Central line is 9 trains per hour to and from Epping.

The National Rail platforms are also served by a separate station building north of the tracks and adjacent to the car park.

Two sidings west of the station to the north of the running lines provide layover facilities for works trains.