Network Rail is seeking a partner to take on a £1.8 billion deal to transform the stretch of railway between London King's Cross and Peterborough.
The introduction of digital technology on the East Coast Mainline between London King's Cross and Peterborough by 2024 will be the country's first major inter-city deployment of ETCS (European Train Control System) signalling to boost capacity and reliability.
This will help make the ability to run trains at 140 mph - compared with 125mph today - a "much more credible proposition", Network Rail route programme director Toufic Machnouk said.
A technology provider will be appointed to work with the Government-owned company to develop a digital signalling system to run for 30 years.
The 100-mile stretch of track between London and Peterborough was chosen for the project because of a "once-in-a-generation alignment of opportunities", according to Mr Machnouk.
Its signalling equipment - some of which dates back to the 1970s - needs renewing at the same time as new trains capable of exploiting digital technology are being introduced.
Performance on the East Coast suffers from old signalling assets and trains, combined with high demand from both passenger and freight operators.
Network Rail predicts that ETCS could lead to an increase from six long-distance trains per hour to eight, and a total of 20 trains per hour through Welwyn Garden City, compared with 16 today.
Mr Machnouk said: "It allows you to run trains closer together, it allows you to have constant communication with a train.
"With other layers like traffic management, it allows you to plan at a superhuman level."
Once the East Coast work has been completed, Network Rail will look to roll out the technology on other routes.
"This will set the mould for how the digital railway is deployed," Mr Machnouk said.
The comparatively early link with another firm on a major project is an "entirely new way of working" for Network Rail.
"There's a need for longer term partnerships and relationships," Mr Machnouk said.
"This cannot just be a small standalone deployment on an input specification where someone rocks up, delivers and walks away, and we're left with assets, kit and technology that we don't know what to do with.
"Fundamentally it needs to be on a whole life, longer term basis, starting very early."
The contract is expected to be awarded in spring next year.