Under its agreement with Ministers, TfL will take over the routes between Liverpool Street, Enfield Town, Cheshunt (via Seven Sisters) and Chingford.
It will also gain control of twenty three of the 25 stations servicing the routes, although Liverpool Street and Cheshunt stations will remain under the control of Network Rail and Greater Anglia.
TfL says it will appoint a private sector company to operate services, as it does on the highly successful and popular London Overground.
Promised improvements include a deep cleaning of stations, including renewal of broken or damaged equipment and redecoration, plus help points and CCTV at all stations and improved customer information.
TfL says it hopes to take over services “during 2015” although no date has been fixed.
Announcing the routes included in his deal with Ministers, Mayor of London, Boris Johnson, said: “You only have to look at the success of London Overground to see how TfL taking over this commuter service will transform the journey for passengers. It will also open up the North-East of London and drive jobs and growth in Tottenham and beyond.”
TfL’s Managing Director for London Rail Mike Brown added: “We will make these services more reliable, upgrade facilities at 23 stations along the routes and ensure we are fully accountable to our passengers.
“There is much work to be done to ensure a transition of responsibilities in 2015 and also to establish a close working relationship with Greater Anglia so that where we share tracks, we are able to operate efficiently.”
TfL says the decision to devolve the services followed “extensive consultation between TfL and Hertfordshire County Council”.
Asked whether the new service would use the London Overground brand, a TfL spokesperson said: “We’ll be looking over the next few months at how best to bring these routes into the TfL family, including whether to brand them ‘Overground’.”
The Mayor’s efforts to also take over the Southeastern franchise are “unlikely” to be successful according to Transport Commissioner Sir Peter Hendy.
In a report to be presented to the TfL board this week, Sir Peter says: “Following discussions between the Mayor and the Secretary of State for Transport, it has become clear that devolution to TfL of rail services in southeast London is unlikely for the time being.”