The Circle, District, Metropolitan and Hammersmith & City lines together make up nearly 40% of the network and include the oldest part of the network built in 1863. As well as circling central London, the lines reach out to suburbs to the West, North West and East of the capital. Between them the four lines carry around 1.3 million passengers a day - more than many European countries carry on their entire rail networks.
These improvements will boost capacity by an average of a third on the four lines and is vital in order to support London's growing population, which is expected to increase from 8.6 million today to 10 million by 2030.
London Underground signaling, control contract awarded to Thales
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 — with frequency increases at other times as well.

Transport for London

Transport for London (TfL) has awarded a contract to global transportation systems provider Thales to modernize the signalling and train control system on the next four London Underground (LU) lines.
This next major phase of the Underground's modernization will bring faster, more frequent and more reliable journeys to millions of passengers who use the Circle, District, Metropolitan and Hammersmith & City lines.
In advance of that, customers are already seeing improved services on the four lines as TfL completes the introduction of the new air conditioned trains on the entire network by 2016. Further benefits will include a train control system which will increase capacity further starting with the Circle line in 2021, with additional frequent services at peak times. During 2023 the final improvements will be delivered, with a further boost to peak and off-peak frequency on the Metropolitan line.
The value of the contract with Thales for the signalling and control work is $1.2 billion.
The overall budget for the four line modernization project, confirmed as $8.4 billion, includes investment in 191 new modern air-conditioned walk-through trains, built in the UK, and already introduced on the Metropolitan, Circle and Hammersmith & City and District lines.
The investment also includes further improvements to get the most out of the new trains, including new track, lengthened platforms and rebuilt train depots with advanced technology to ensure the highest levels of train reliability.
More Rail

New York MTA Leverages Zoning Program to Advance Station Accessibility
Accessibility enhancements at Nevins St Station will be financed through a development agreement tied to the MTA's Zoning for Accessibility initiative.
Read More →
Virginia's $28.5B Transportation Plan Targets Transit and Rail
Approved by the Commonwealth Transportation Board, the program supports ongoing infrastructure projects while providing new investments in transit, state of good repair and transportation alternatives.
Read More →
DOT: Brightline Corridor Incidents Fall 30% Following Federal Safety Upgrades
Safety improvements funded through a $25 million federal investment are credited with reducing trespassing and train-vehicle collisions along the Brightline Florida corridor.
Read More →
D Line Expansion Fuels Growth Across LA Metro's Rail System
Weekend rail ridership was especially strong, soaring 18% as riders embraced expanded access to jobs, entertainment, dining, and cultural destinations, said the agency. Total system ridership for May, including bus and rail, was 26,966,657.
Read More →
Southern California's Metrolink Debuts Contactless Fare Payment Pilot
Customers traveling between Redlands and Los Angeles can now tap their preferred payment method, including a credit or debit card, mobile wallet, or wearable device, at station validators before boarding and again while exiting.
Read More →
California's BART Approves FY27 Budget While Maintaining Service Levels
The budget covers July 1, 2026, through June 30, 2027, a period when pandemic emergency funds run out, the District faces a structural deficit of $375 million, and a regional transit funding measure may appear on the November ballot.
Read More →
Penn Station Transformation Advances with Design Unveiling
The historic redesign will transform the busiest transit hub in the Western Hemisphere from the tracks to the street level, creating a more efficient, cleaner, and functional experience for more than 600,000 daily commuters and millions of visitors.
Read More →
Second Avenue Subway Phase 2 Advances into Major Construction Stage
New York Governor Kathy Hochul joined leadership from the MTA, elected officials, and Harlem community leaders to break ground on the major construction stage of the transformative Second Avenue Subway Phase 2 project.
Read More →
The Invisible Infrastructure of Passenger Flow
What a seat reservation system on Austria’s Railjet trains reveals about the future of rider experience, and why U.S. agencies should pay attention.
Read More →
Caltrain Board Approves FY27 Budget, Endorses Efficiency Measures
The move ensures Caltrain service will continue operating as usual in the near term, but long-term financial challenges remain for the rail agency absent a new revenue source.
Read More →