London 4 Line Modernisation

Modernising the London Underground


Upgrade will boost peak-hour capacity by 33% across four key lines

Transport for London (TfL), the organisation responsible for transport in the UK capital, is investing in capacity enhancements to accommodate rising passenger numbers. One of these is the transition to communications-based train control (CBTC) signalling that makes it possible to increase the frequency and speed of train services on existing lines.
TfL is working with Thales to implement SelTracTM CBTC signalling across the District, Circle, Hammersmith & City and Metropolitan lines – four of London’s busiest routes.
Modernisation will deliver faster and more frequent journeys for millions of passengers, with capacity on the lines boosted by a third. Passengers are already benefiting from new trains, which have now been introduced on all four lines.
2017 will see trains being fitted with new onboard signalling equipment and in 2018 the new Hammersmith Service Control Centre will be ready for staff training. The first section of the new signalling is scheduled to go live in 2019. The main benefits will be delivered by 2022, when the frequency of trains running during peak periods will increase to 32 trains per hour in central London – a train every two minutes.

The District, Circle, Hammersmith & City and Metropolitan lines account for 40% of the London Underground network

All four lines share track and signalling

Some existing signalling infrastructure is more than 90 years old

Project includes new signalling for the world’s first metro route – the Metropolitan Line – opened in 1863

Upgrade is one of the biggest and most complex ever carried out on a metro system