Before the M25 was finished, a search was held for potential service station sites. The plan was to reserve an infill 'Leatherhead services', and to build full services at Chevening, and at the western side.
Closely spaced junctions and flyovers made finding a suitable site on the western section difficult. It was eventually decided the only option was to build a full service area to the west of J14, which at the time was the exit for a spur road to Heathrow. This was Poyle services, although it later became Colnbrook. It was included in the M25 public inquiry as part of the Heathrow junction.
Poyle services would have been neatly tucked between the motorway and the reservoir. However, the services would have cut off a path accessing a local park, and although alternatives were considered, this eventually caused Poyle to be dropped as a proposal. With the opening of the M25 moving closer, Iver was analysed.
Meanwhile, Leatherhead was dropped and sites were considered at New Haw and a popular option at Walton-on-the-Hill.