London is the centre of an extensive radial commuter railway network which, along with Paris, is the busiest and largest in Europe, serving the surrounding metropolitan area.
Each terminus is associated with commuter services from a particular segment of this area.
The majority of commuters to central London (about 80% of 1.1 million) arrive by either the Underground (400,000 daily) or by surface railway into these termini (860,000 daily).

For historical reasons, London's commuter rail network is arranged in a radial form, and as a result the majority of services entering London terminate at one of the terminal stations around the edge of the city centre.

In contrast to the more developed regional RER network in Paris, only two long-distance National Rail lines currently go across London: the Thameslink route runs between the more distant towns of Bedford in the north and Brighton on the south coast, passing through the City of London, London suburbs as well as Luton Airport Parkway and Gatwick Airport, while the West London Route goes via Shepherd's Bush and is operated by Southern running between Milton Keynes Central in the north and East Croydon in the south.
 A major expansion of the Thameslink route is planned 2013–18, in which a number of existing regional rail services will be redirected via the cross-London Thameslink corridor.

Constantly increasing pressure on the commuter rail systems and on the Underground to disperse passengers from the busy terminals has led to the multibillion-pound Crossrail scheme.
When completed, Crossrail will add a further cross-London line passing through Paddington and Liverpool Street.
Construction work is currently underway, and twin 16-km tunnels are being bored underneath the city centre.
New or upgraded stations will be provided at key city centre locations, linking to the Underground.

While most stations in central London are termini, there are a few notable exceptions.
London Bridge station has several through lines to the more central termini at Cannon Street and Charing Cross, and trains to the latter also call at Waterloo East, linked to Waterloo by a footbridge.
London Bridge's through platforms are also used by the Thameslink services of Govia Thameslink Railway, which cross the city centre, calling at Blackfriars, City Thameslink, Farringdon and St Pancras.
London is the centre of an extensive radial commuter railway network which, along with Paris, is the busiest and largest in Europe, serving the surrounding metropolitan area. Each terminus is associated with commuter services from a particular segment of this area. The majority of commuters to central London (about 80% of 1.1 million) arrive by either the Underground (400,000 daily) or by surface railway into these termini (860,000 daily).
For historical reasons, London's commuter rail network is arranged in a radial form, and as a result the majority of services entering London terminate at one of the terminal stations around the edge of the city centre.
In contrast to the more developed regional RER network in Paris, only two long-distance National Rail lines currently go across London: the Thameslink route runs between the more distant towns of Bedford in the north and Brighton on the south coast, passing through the City of London, London suburbs as well as Luton Airport Parkway and Gatwick Airport, while the West London Route goes via Shepherd's Bush and is operated by Southern running between Milton Keynes Central in the north and East Croydon in the south.  A major expansion of the Thameslink route is planned 2013–18, in which a number of existing regional rail services will be redirected via the cross-London Thameslink corridor.
Constantly increasing pressure on the commuter rail systems and on the Underground to disperse passengers from the busy terminals has led to the multibillion-pound Crossrail scheme. When completed, Crossrail will add a further cross-London line passing through Paddington and Liverpool Street. Construction work is currently underway, and twin 16-km tunnels are being bored underneath the city centre. New or upgraded stations will be provided at key city centre locations, linking to the Underground.
While most stations in central London are termini, there are a few notable exceptions. London Bridge station has several through lines to the more central termini at Cannon Street and Charing Cross, and trains to the latter also call at Waterloo East, linked to Waterloo by a footbridge. London Bridge's through platforms are also used by the Thameslink services of Govia Thameslink Railway, which cross the city centre, calling at Blackfriars, City Thameslink, Farringdon and St Pancras.
Transport in London