DOUBLE decker trains and rail speeds of up to 125mph are among the proposals of a major plan for the line from London to Dorset.

The public is being asked to comment during a 90-day consultation on the Wessex Route Study, which lays out ideas for increasing capacity on the lines between Waterloo and the south and south west.

It has been put together by Network Rail on behalf of a joint industry group including Transport for London, the Department for Transport and the train and freight operators.

Tim Shoveller, chief executive of the Network Rail-South West Trains Alliance, said: “Our railway already carries more than 220million passengers a year, and that number is predicted to grow significantly in the years ahead.

“Work we are already doing over the next five years will make a huge difference, including lengthening suburban trains and reopening the Waterloo International Terminal. But we need to do more, and do it quickly.

“The plans we are proposing in this study mean we will be able to cope with a forecast growth of 40 per cent on main line services over the next 30 years. We are also looking at what kind of improvements we can offer in reliability and frequency by introducing new technology which will allow us to improve the network further.

“It’s fantastic that more and more people want to travel by train and we want to provide the railway to take them where they are going.”

The study identifies priorities for the years 2019 to 2024 and looks ahead as far as 2043. Key proposals include double-decker trains, electrification of the line to Salisbury, speeds of 125mph on some sections of track, extra platforms at Southampton Central and Guildford and development of cab-based signalling and automatic train operation.

It covers the routes from Waterloo to Reading, Southampton, Weymouth, Portsmouth and Exeter as well as suburban services around the capital. None of the proposals in the study are funded, but it does include some initial costs and business case assessments.

The draft study is available at networkrail.co.uk/long-term-planning-process/Wessex-route-study.

The final document will be published in summer 2015.