services on the Great Western Main Line terminate at Bristol, while others continue on the Bristol to Exeter line towards the West Country. The other branch to the west of Reading station is the Reading to Taunton line (the "Berks and Hants" line), which serves communities in Berkshire and Wiltshire. High speed services on this line do not normally call at all stations along the route (except sometimes and ), and some express services from the South West operate non-stop between Paddington and . The Reading to Taunton branch joins services travelling south from Bristol on the Bristol to Exeter line at Cogload Junction, to the north of Taunton. The line proceeds to serve the stations of Taunton, , and onward to stations in Cornwall such as where the branch to diverges where some trains terminate whilst most terminate at the terminus of Penzance. Both high-speed intercity services and local services are operated by Great Western Railway. Nearly all services are timetabled to stop at Reading. Other main lines connect Reading with , and northern England, and with , , and to the south. Through services from north to south on these lines are operated by CrossCountry, and all services stop at Reading, which requires the trains to reverse in the station. The main routes offered by CrossCountry are to and to the north and Southampton Central and in the south. The Elizabeth line operates a service to Abbey Wood, stopping at most stations to Ealing Broadway. On Sunday mornings and Sunday nights, trains terminate at London Paddington instead. The secondary North Downs Line connects Reading with , , and . Services on this line, together with local stopping services to , , , and London Paddington, are also operated by Great Western Railway. An electric suburban line operated by South Western Railway links Reading to , , , , Richmond, and . Pending the construction of the direct rail route to Heathrow Airport, an express bus service, RailAir, links Reading to London Heathrow Airport, as do suburban services via Hayes & Harlington. Proposed Heathrow Airport links Reading station was intended to be the western terminus for the proposed Heathrow Airtrack rail service. This project, promoted by BAA, envisaged the construction of a spur from the Waterloo to Reading Line to Heathrow Airport, creating direct rail links from the airport to Reading, London Waterloo, and Guildford. Airtrack was cancelled by