The HS2 high-speed rail project being approved by the government today is seen by ministers as "a once-in-a-generation opportunity to transform the way we travel in Britain".
Trains travelling at 225mph would cut the London to Birmingham journey time to 49 minutes when the first phase of the £32 billion project is completed by 2026.
Then a second phase would see HS2 proceeding on a Y-shaped route to take in Leeds and Manchester, with this northern sector being completed by 2032/33.
The government envisages stops in the East Midlands and South Yorkshire and links to the existing West Coast and East Coast main lines which would enable through-running services to reach Liverpool, Newcastle upon Tyne, Glasgow and Edinburgh.
Journey times from London to Scotland's major cities would be cut to around three hours 30 minutes, while London-Manchester and London-Leeds journey times would be reduced to 80 minutes.
There would also be a link to the cross-London Crossrail scheme at Old Oak Common in north-west London as well as a possible spur to Heathrow airport.
In addition, the government favours a direct rail link between HS2 and the London to Channel Tunnel HS1 high-speed route.
This link would run in a tunnel from Old Oak Common to the North London Line and then use existing infrastructure to reach the HS1 line north of St Pancras station in London.
Full coverage of the HS2 decision by the government:
The government believes that the whole HS2 project will generate economic benefits of almost £44 billion over a 60-year period.
It also estimates that the first phase alone will support the creation of around 400,000 jobs as well as contributing to the major regeneration programmes in Britain's inner cities.
The government also believes that the enhanced capacity created by HS2 could see as many as six million air trips and nine million road trips a year shift on to rail.
Trains would be up to 400 metres (1,312ft) long and have as many as 1,100 seats, with up to 14 running an hour in each direction, with this number possibly increasing to 18 an hour.
The HS2 route will start at a rebuilt Euston station in London and would run, in the first phase, as far as a new Birmingham city centre station at Curzon Street.
A second interchange station would be constructed where the line of the route passes the National Exhibition Centre (NEC) and Birmingham airport close to junction six of the M42.
It would offer direct links to Birmingham airport, the NEC, the M6 and M42.
Most controversy about the scheme has centred on its route through the Chilterns. It is thought the government will announce more of the route will run in tunnels to try to alleviate the worst effects of the scheme.