Sheffield to Manchester £6bn road tunnel may be 'longest in Europe'
A major road and rail tunnel through the Peak District could be the longest tunnel in Europe, a report says.
The scheme to bore through the Peak District to improve links between Sheffield and Manchester is feasible, but further investigation is needed.
Such a tunnel would result in quicker journey times and avoid delays caused by poor weather in the winter months.
Highways England, which produced the report, said a more in-depth study will be ready by the autumn of 2016.
The government study looked at the feasibility of tunnelling under the A628 Woodhead Pass, in a scheme which would reportedly cost £6bn.
The document says it is possible the tunnel could cut current road journey times by up to 30 minutes and avoid the delays caused by bad weather over the Pennines .
The planned new link between Sheffield and Manchester would "include a tunnelled section, which could range from between 20-30km (12.4 -18.6 miles), making it one of the longest road tunnels ever built."
The authors say: "The construction of a new strategic road link between Manchester and Sheffield is technically feasible, although it is likely to include a tunnel (or series of tunnels) that could be longer than any road tunnel constructed in Europe to date."
The paper's preliminary findings include: "The development of a combined road and rail corridor through the tunnelled section could offer some additional benefits, although road and rail would need to occupy separate tunnel bores and we have not yet established the operational case for this type of solution."
Although the paper only looks at the early ideas for such a scheme, Highways England said no means of funding the plan had yet been identified, but there could be a toll levied on tunnel users.
The report says: "We have not had time yet to do any transport modelling of benefits and costs from a trans-Pennine tunnel.
"The analysis presented in this report is purely to determine whether there is a case to do more intensive work on investigating tunnel options."
Highways officials said the tunnel would need to have an operational life of 120 years and "anticipate quite radical changes in technology and tunnel use".
"Our initial conclusion is that, in tunnel sections additional bores would be required to accommodate rail alongside road.
"Light rail could, in principle, share road space with highway traffic, but low operating speeds and the fact that this mode is more suited to dense urban areas, may make it undesirable."
The options in the report are separate from the Department of Transport's £15bn package to transform major roads across England.
The final report looking at the transport, social, economic and environmental aspects of the scheme will be produced in October 2016.