Atoc says record demand has led to the need for investment
Train operators are calling for widespread expansion of the rail network in England, with 14 extra lines and about 40 new stations proposed.
The Association of Train Operating Companies said there was a need for expansion to cope with rising demand.
It said the expansion, which would cost £500m and possibly reuse lines closed under the 1960s Beeching cuts, could serve more than 1m extra passengers.
Any decisions on future expansion rest with government and Network Rail.
Atoc chief executive Michael Roberts said: "Record passenger numbers and rising demand require us to plan for the long term, while climate change and population growth make it vital that in doing so, we adapt the rail network to meet tomorrow's needs.
"Providing attractive new services and easier access to the rail network will encourage passengers to switch to rail from other, less green, modes of transport.
"We have established that there is a strong business case for investment to bring a number of towns back on to the rail network.
"Now we need to safeguard these routes and develop the detailed case for investment."
The Beeching report by Dr Richard Beeching in the 1960s resulted in the railway network being cut by a third, closing 2,000 stations and 5,000 miles of track.
The Atoc report says 40 towns not currently on the rail network could benefit from the 14 new lines.
It says the new stations could be operational within five to 10 years.
Any decision on whether any of the plans get the go-ahead would be taken by local and regional government, Network Rail and the Department for Transport.
Atoc argues infrastructure from some of the old lines closed in the 1960s could be refurbished to form part of the new network.
Freight lines could also be adapted to serve commercial routes, it said.
Transport Minister Chris Mole said the government would consider the findings of Atoc's report.
"The government's priority is to bring about changes, such as capacity improvements, which will deliver benefits for rail passengers now," he said.
"For the longer term, we will work with local authorities who want to improve links to the rail network, and will plan to make funding available from 2014 for successful schemes which demonstrate value for money."
Shadow transport secretary Theresa Villiers said the research was "interesting" and made "an impressive case" for reopening disused rail lines.
She added: "Conservatives recognise the value of these transport corridors, which is why we have called for a moratorium on building on any disused rail lines still in public ownership.
"Certainly, housing growth and the need to cut emissions from transport and tackle road congestion means that all political parties should look seriously at the ideas put forward in this report, though it is clear that the state of the public finances will put constraints on what is possible over the next few years."
Bob Crow, general secretary of the Rail Maritime and Transport union, said: "RMT has repeatedly called for an expansion of rail services to create green jobs and green transport options as part of our campaign for a people's railways.
"However, any expansion should be publicly-owned and free from the chaos and profiteering of the privatised franchise system."
The areas which would be served by the 14 possible new lines identified in the report are:
• Cranleigh in Surrey
• Bordon, Hythe and Ringwood in Hampshire
• Brixham in Devon
• Aldridge and Brownhills in the West Midlands
• Wisbech in Cambridgeshire
• Leicester to Burton in the East Midlands
• Fleetwood, Rawtenstall and Skelmersdale in Lancashire
• Washington in Tyne and Wear
• Ashington and Blyth in Northumberland