Plans for an 'HS3' to improve east-west rail journeys across northern England are more than just about "eye-catching" journey-time reductions, according to the boss of HS2.
The HS3 scheme, which could cost about £7 billion, was "not just a single project", said HS2 Ltd chairman Sir David Higgins.
He has put forward the HS3 plans in a report incorporating further plans for phase two of the £50 billion HS2 high-speed rail project.
HS3, which is backed by prime minister David Cameron and chancellor George Osborne, would mean journey times between Leeds and Manchester could almost be cut in half.
Journeys between Leeds and Birmingham, Leeds and Sheffield Meadowhall, York and Birmingham and Nottingham to Birmingham could also be reduced by a half or more, and many more journeys across the country substantially shortened.
Sir David told BBC Radio 4's Today programme that his plans for HS3 were "a start of a conversation".
He said: "This is not just a single project. It's more than the eye-catching journey-time reductions. HS3 will give northern England rail services twice the capacity and much more reliability."
Phase one of HS2 involves a new high-speed line from Euston in London passing through the Chilterns to Birmingham, which would be completed in 2027.
Phase two would see the line extended north from Birmingham in a Y-shaped route going to Manchester and Leeds, which would be finished in 2033.
Sir David's report said there was a need to take forward both legs of the proposed HS2 Y-network as the alternatives would not bring the same capacity, connectivity and economic benefits;
For HS3, the journey from Leeds to Manchester could be cut from today's average of more than 55 minutes to somewhere between 26 and 35 minutes and the number of trains could be doubled.
For phase two of HS2 Sir David's recommendations include:
- To continue with the planned route into Manchester city centre via the airport - keeping open the option to add a new airport station;
- Need to review the best station solution for Leeds to include provision for increased east-west services through the city;
- The HS2 line should be extended to Crewe by 2027 - six years earlier than originally proposed;
- A new station at Sheffield Meadowhall remains the best way to serve the wider South Yorkshire region, though Sir David recognises Sheffield continues to argue for Sheffield Victoria;
- That the East Midlands hub should be near the proposed site at Toton but that its precise location needs further work.
Sir David said: "Improving connectivity is vital if Britain is to compete in the knowledge economy in which this country has a competitive advantage, but in which ease of travel is an essential element.
"On the back of new transport infrastructure, science investment and civic leadership, we are well on our way to turning the northern powerhouse into reality."
The project is strongly supported by the government but is bitterly opposed by some councils and residents along the phase one route.
Cameron said: "Improving connectivity and reducing journey times between our great northern cities is a crucial part of our long-term economic plan for the north to boost businesses and create more jobs and security for hard-working people. That's why we are backing HS3.
"I welcome Sir David Higgins' report, which will help our work to create a northern powerhouse and ensure that HS2 delivers the maximum economic benefits."
Deputy Prime Minister Nick Clegg, Transport Secretary Patrick McLoughlin and Chief Secretary to the Treasury Danny Alexander also welcomed the report, as did House of Commons Transport Committee chairman Louise Ellman.
Dr Colin Brown, director of engineering at the IMechE, said: “Creating a high speed link between Manchester and Leeds could help bridge the North South economic divide more quickly, so it is welcome that the government has backed these proposals.
“But we need the government to show even greater ambition. The time-scales for these projects and the long lead times to getting approval, mean we’ll be well into the next century before we have a properly integrated and efficient transport system."
Dr Brown added: “We need to develop a clear strategy for sustainable and resilient transport links across the country, which incorporates new airport, road and rail infrastructure. We need more than piecemeal projects if the UK is going to have a transport system fit for the 21st century.
“Having a clear plan provides confidence and allows for forward planning, which is critical for keeping costs down. The skills need for such major projects cannot be created overnight. The talent and expertise from people delivering projects like Crossrail are national assets which must not be lost forever through a lack of vision.”
Stop HS2 campaign manager Joe Rukin said HS3 would be even more expensive per mile than HS2. He added that Sir David's report "showed that the original plans for HS2 weren't thought through properly".
Rukin went on: "Changing the mess that is phase two doesn't change the fact that phase one is still a complete mess, as is the entire concept of HS2."