The Channel Tunnel runs under the English Channel between
Cheriton, near Folkestone in England, and Coquelles, near Calais
in France. It opened to traffic in 1994. The Tunnel is actually
three parallel tunnels, two rail tunnels with a service and
emergency tunnel in between. In normal operation, one rail
tunnel is used by traffic in each direction, but in exceptional
circumstances trains can run in either direction in either
tunnel. Crossovers between the tunnels facilitate this form of
operation. These are housed in giant caverns excavated below the
seabed. The tunnel carries passenger and freight rail traffic
between Great Britain and continental Europe, and also a service
of shuttle trains conveying road vehicles between terminals at
each end of the Tunnel. When Eurostar passenger services
commenced, they operated over existing railways in England
between the Channel Tunnel portal and London Waterloo station.
This route was subject to many speed restrictions and frequent
pathing conflicts with other servic