Siemens Mobility, in collaboration with L.K. Comstock (LKC) — an electrical contractor specializing in rail transit systems — was awarded a contract by the Metropolitan Transportation Authority (MTA) to modernize New York City’s Fulton-Liberty Lines with advanced Communications-Based Train Control (CBTC) technology.  

The Siemens CBTC System, Trainguard MT, in compliance with New York Subway Interoperability Interface Specifications (I2S), enables trains to run as close as 90 seconds apart, using next-generation signaling and continuous communication to keep operations moving seamlessly.

The new technology is expected to boost capacity, reduce wait times, and provide the flexibility needed to meet future demand on these two busy subway lines, while preparing the network to keep New Yorkers on the move for decades to come. 

MTA’s Fulton-Liberty Line

The transformative upgrade will connect 23 stations and replace nearly century-old infrastructure to enhance the commute across Brooklyn and Queens with an energy-efficient solution. 

Running primarily along a four‑track alignment, multiple trains can operate simultaneously on the Fulton-Liberty Lines — meaning that while together they span approximately 15 miles in length, the total track distance equates to nearly 40 track miles.  

“Modernizing the Fulton-Liberty Lines is more than a technology upgrade — it’s a step to improve the everyday commute for millions of New Yorkers,” said Tobias Bauer, CEO of Siemens Mobility North America. “Siemens Mobility’s CBTC technology will provide enhanced safety, on-time performance, capacity, and scalability for trains running across the network. That means faster, more reliable service across New York.” 

About the Project

As part of the signal modernization, LKC will decommission all signaling and associated equipment that the Train Control System replaces.

The scope of work includes installing and replacing 24 new Special Work Portions, 94 switch machines, and constructing four new train control rooms. The upgrades require LKC to install 4 million feet of cable throughout the tunnels and within the newly built facilities.  

The project introduces 5G commuter cellular service, ensuring riders remain connected as they travel between stations. LKC will install a Distributed Antenna System and supporting fiber cabling in the underground tunnel portion of the project, which spans 62 track segments with work in 18 stations.    

Once the system modernization is complete, Siemens Mobility will also support its long-term performance and reliability through a 25-year maintenance commitment to the MTA with the option for two additional five-year extensions.

Boosting Mobility

The Fulton-Liberty Lines serve as vital arteries in New York City’s sprawling transit network. Starting at Jay Street-MetroTech Station, the Fulton Street Line travels through Central Brooklyn. Then it connects to the Liberty Avenue Line, which begins at Euclid Avenue Station and concludes in Ozone Park, Queens, linking multiple major subway lines along the way.

Built in the 1930s and 1940s, this historic subway corridor is now at the heart of the MTA’s vision for a future-ready, resilient transportation system. The A (Express) train runs along the Fulton-Liberty Lines for a significant portion of its route in Brooklyn and Queens, while the C (Local) train uses the Fulton Line for its entire route in Brooklyn. 

As part of the modernization project, Siemens Mobility will deploy Trainguard MT to seamlessly integrate nine subway interlockings across the two separate subway lines. This includes replacing outdated track circuits with innovative axle-counter technology and introducing 5G-based radio communications to enable real-time, optimized train control.