The Y-shaped network will consist of an initial 190km phase called High
Speed Two (HS2) linking London and Birmingham, with future extensions
northwest to Manchester and northeast towards Sheffield and Leeds. The
total cost of the project is expected to be around £30 billion,
although the government says it will examine how construction costs can
be reduced.

The plans have been developed by High Speed Two
Limited (HS2L), a company established by the government last year to
look at options for a high-speed line between London and Scotland.

will start at London's existing Euston station, which will undergo a £1
billion reconstruction with 10 high-speed platforms and 14 platforms
for conventional rail services. From Euston the line will run west to a
new station at Old Oak Common, which will act as an interchange for
Heathrow Express, Crossrail, and mainline services to the west. HS2
will then follow the existing Chiltern mainline through Ruislip before
proceeding past Aylesbury, Brackley and Leamington Spa to Water Orton.
Here the line will divide with a link to the conventional network for
trains running into Birmingham, while the main line will continue north
to a junction with the West Coast Main Line near Lichfield, allowing
trains to continue to Manchester, Liverpool and Glasgow.

The only
intermediate station on HS2 will be an interchange southeast of
Birmingham, which will serve the city's airport and National Exhibition
Centre, as well as the M6 and M42 highways.
A new city-centre terminus will be built at Curzon Street, close to the existing New Street and Moor Street stations.

will have a design speed of 400km/h and trains will operate at up to
360km/h from the outset. The line will initially have capacity for up
to 14 trains per hour, rising eventually to 18 trains per hour.

times between London and Birmingham will be reduced from 1h 24 min to
49 minutes. The cost of the initial phase is projected to be between
£15.8 billion and £17.4 billion. HS2L has calculated the project has a
benefit:cost ratio of 2.4:1, much higher than the Department for
Transport's threshold of 2:1.

The government proposes introducing a
Hybrid Bill in Parliament that, subject to approval, would allow
construction to begin following the completion of London's Crossrail
project in 2017. Trains would begin running on the London - Birmingham
section in 2026. The outcome of a general election, which is due to be
held before June, could affect this timescale, although all three main
political parties have declared their support for a high-speed line.

government now wants HS2L to take the project to the public
consultation stage by the autumn, and begin developing plans for the
lines to Manchester, Sheffield and Leeds. Consultation will begin on
these lines in 2012.