Ascot–Ash Vale line

There is a section of single track from just south of Frimley station (and north of the South West Main Line between Brookwood and Farnborough Main) and Ash Vale Junction. The rest of the route is double-tracked.

The line is electrified using 750 V DC third rail.

Route of the Ascot–Guildford service

Passenger services on the line used to run from Ascot to Guildford continuing via the Alton line and the North Downs Line. Ascot station is located on the line from London Waterloo to Reading, just to the south of the famous racecourse. From here, services travel a short distance west along the Waterloo to Reading Line to Ascot Junction. Here they turn south and travel to Ash Vale Jn, joining a section of the Alton Line as far as Aldershot. Services then retrace its route back along the Alton Line before joining the North Downs Line via a chord between Aldershot North Jn to Aldershot South Jn for the remainder of the journey to Guildford.

Until 2017, pairs of Class 456, transferred from Southern, used to operate the shuttles between Ascot and Guildford (turning around at Aldershot). The trains have since been replaced by Class 450s.

The Monday to Saturday service prior to May 2019 was:

• 2 trains an hour between Guildford and Ascot stations during the day, in the evening 1 train per hour.
• The first trains towards Ascot start from, and the last trains terminate at, Farnham railway station or Aldershot railway station.
• Some trains during the Morning and Evening peaks, Monday to Friday, travel to/from London Waterloo station joining the Waterloo–Reading line at Ascot station.

On Sundays an hourly service ran.