VGF and Siemens Mobility have announced progress in the digitalization of Frankfurt’s urban rail system with the introduction of Communications-Based Train Control (CBTC) technology. Over the past year, a prototype metro train has been undergoing semi-automated test runs at VGF’s central depot as part of the Digital Train Control System Frankfurt (DTC) project. The prototype operates at “Grade of Automation 2,” which allows for partial automation under driver supervision.
Starting in 2027, VGF plans to gradually implement this digital control system across its network. CBTC technology will enable continuous communication between trains and track infrastructure via radio signals. This shift will allow trains to operate in a “moving block” system, maintaining safe braking distances rather than relying on fixed block sections. As a result, more trains can run on existing tracks without requiring new construction or major modifications.
The new system is expected to improve schedule reliability and precision while reducing energy consumption by up to 25 percent. It also aims to decrease wear on vehicles and tracks and enhance passenger comfort through smoother acceleration and braking.
Wolfgang Siefert, Head of Mobility, commented: “I am pleased that the DTC digitalization project has reached this milestone, and we will now see in practice what we’ve been discussing in theory for years. This is good news for Frankfurt: The automated prototype tests show that the digital transformation can drive urban mobility. Specifically, DTC will make public transportation more efficient, reliable, economical, environmentally friendly, and even more comfortable.”
Integration with road traffic systems is another key aspect of the project. Since some metro lines operate above ground, VGF has coordinated DTC with the city’s “Frankfurt MIND(+)” initiative—a multimodal mobility project using Cooperative Intelligent Transport System (C-ITS) technology. The interface between CBTC and C-ITS was tested successfully on VGF’s test ring.
Steffen Geers, Managing Director at VGF, stated: “We are pioneers here and the first transport company worldwide to connect these two technologies. For VGF, DTC is one of the most important innovation projects, and a technology with which we will be future-proof for years to come.”
Guido Rumpel, Head of Rail Infrastructure Germany at Siemens Mobility added: “With our modern CBTC technology Trainguard MT, we are making Frankfurt’s public transport fit for the future. Trainguard MT enables more trains to run at shorter intervals through semi-automated operation. This provides up to 30 percent more capacity with technically possible train sequences of less than 100 seconds, increases energy efficiency, and significantly improves punctuality. This technology has already been proven in cities such as Paris, New York, and Singapore – and it is now being used in Frankfurt.”
The necessary technology has already been installed on lines U4 and U5 between Bockenheimer Warte and Seckbacher Landstraße tunnels. Static system tests are scheduled for September and October 2025; initial test runs without passengers are planned for January 2026. Full implementation on lines U4 and U5 is expected by 2027; additional routes including U1-U3/U8 (“A-Route”), C-Route lines, and trams are scheduled for completion by 2033.
VGF serves as Frankfurt’s main public transport provider with over 182 million passengers transported annually across nine metro lines and ten tram routes spanning more than 133 kilometers.
Siemens Mobility operates as an independent entity within Siemens AG specializing in intelligent transport solutions globally; it reported €11.4 billion revenue in fiscal year 2024 with approximately 41,900 employees worldwide.
The DTC project aims to enhance both signal safety and operational efficiency through advanced train control technologies while integrating seamlessly into broader city mobility initiatives like MIND(+) that promote sustainable urban transportation.
