10 questions, 10 answers: V2X in Traffic Management with Kathrin Hagemann

1. Kathrin, what personally fascinates you about V2X technology, and why is it so relevant for public transportation?

V2X is the first technology that directly connects road users dynamically with the road infrastructure.

What fascinates me most is that it transforms a transportation system made up of many individual, largely independent components into a cooperative, intelligent ecosystem. That is exactly where the term Cooperative Intelligent Transport Systems (C-ITS) comes from.

What excites me most about C-ITS is the combination of diversity and collaboration. The technology covers everything from public transport prioritization and hazard warnings to intelligent traffic management and applications that, in some cases, have not even been realized yet. As a result, there are constantly new challenges, new use cases, and I am still learning something new every day.

At the same time, V2X is a success story of European collaboration. For more than 20 years, experts from across Europe have worked together to develop standards that enable vehicles, infrastructure, and traffic management systems to communicate seamlessly across platforms. Personally, I still find it incredibly rewarding to exchange ideas with people from different countries, disciplines, and companies.

2. Can you explain public transport prioritization via V2X in one sentence?

With V2X-based public transport prioritization, vehicles and traffic signals communicate digitally and bidirectionally for the first time, making transit prioritization more dynamic, future-ready, and flexible.

3. What advantages does V2X offer compared to traditional prioritization methods such as induction loops or infrared systems?

V2X offers significant advantages in maintenance, flexibility, and versatility.

From a maintenance perspective, V2X components are far easier to manage. For example, a faulty induction loop often requires extensive roadworks and can lead to long outages, whereas V2X devices are designed to be robust and can be accessed directly for servicing and diagnostics.

Another key advantage is flexibility. Traditional systems provide information to traffic signals only at specific detection points. Connected Mobility, on the other hand, enables continuous data exchange, including information such as a vehicle’s expected arrival time. This allows prioritization strategies to be continuously adapted to real-time traffic conditions.

Finally, there is versatility. The same V2X infrastructure can support a wide range of applications beyond prioritization, from traffic quality analysis and green-wave coordination to safety features such as pedestrian alerts and red-light warnings. Once the technology is in place, many additional use cases can be added later through software updates.

4. What does V2X specifically do for public transportation? How does it improve reliability, punctuality, and efficiency, and what is its biggest benefit for cities, operators, and passengers?

V2X makes public transport prioritization smarter, more dynamic, and more transparent. Through bidirectional communication between vehicles and traffic signals, both sides always know what the other is doing.

Instead of relying on information from individual detection points, traffic signals can continuously consider real-time data such as expected arrival times or delays. This enables much more precise prioritization, improves traffic flow, and helps buses and trams operate more reliably and punctually.

V2X also goes far beyond traditional prioritization. Vehicles can receive departure recommendations, for example, to reach an intersection exactly when the signal turns green. This reduces unnecessary braking and acceleration, improves passenger comfort, and saves energy.

For me, the greatest benefit is that everyone wins: cities benefit from more efficient traffic flow, transit operators gain more reliable operations, and passengers enjoy a more punctual and comfortable journey.

5. What role does V2X play in the mobility transition and in making public transportation more attractive?

V2X can help make sustainable modes of transportation more attractive. When buses and trams become faster, more punctual, and more reliable, passengers benefit directly.

That is where I see one of V2X’s greatest opportunities: traffic can be managed more intelligently, while public transportation and cycling can be specifically supported and strengthened.

6. What unique solutions does Yunex Traffic offer in this area, and what sets us apart from others?

What distinguishes us most, in my view, is our understanding of the entire transportation ecosystem. We do not just develop V2X components; we also develop traffic signal controllers, traffic management systems, and traffic control solutions. This allows us to think across systems from the very beginning and create solutions in which vehicles, infrastructure, and traffic management work together seamlessly.

At the same time, we were the first manufacturer to implement the European C-ITS security requirements defined by the EU C-POC for both roadside units (RSUs) and onboard units (OBUs). For a connected technology like V2X, security is a critical foundation.

For me, this combination is what makes the difference: we do not just understand V2X communication itself, but also the interaction between vehicles, infrastructure, and traffic management. That allows us to develop solutions that go beyond individual components and create real value across the entire system.

7. Is there a project that particularly demonstrates how V2X prioritization works in practice?

One example with a particularly large number of equipped vehicles is the city of Graz. Following the phase-out of the analog radio frequencies previously used for prioritization, all buses and trams were equipped with our OBUs.

Today, all prioritization is handled through V2X. At the same time, the city now has access to a wealth of additional information about traffic conditions and the operational status of public transport vehicles.

8. What challenges do you encounter most often, and how do you solve them?

That is a great question. When I joined Yunex Traffic, I assumed public transport prioritization was fairly straightforward: send a request, process it, and you’re done. In reality, there is much more to it.

Every intersection and every traffic signal has its own requirements, while many different components must work together perfectly, from the onboard computer and OBU to the RSU and traffic management system. There are also numerous implementation options and configurations that need to be considered.

Naturally, things do not always work perfectly the first time. The devil is often in the details. The good news is that our team is highly committed, and we collaborate closely with our partners, such as onboard computer manufacturers. Through detailed analysis and excellent coordination, we always find a solution.

9. What misconception about V2X would you most like to dispel?

One misconception I would like to challenge is the idea that V2X is simply an expensive solution for public transport prioritization.

Of course, implementation requires investment. What is often overlooked, however, is how many additional applications become possible once the technology is in place. These range from localized hazard warnings and richer traffic management data to rail switch control and the protection of pedestrians and cyclists.

Once V2X infrastructure has been deployed, many of these functions can be added step by step through software updates. To me, that is the real strength of V2X: you are not investing in a single use case; you are creating the foundation for solving many different transportation challenges.

10. What should cities and public transport operators do today to prepare for a V2X-enabled future? What developments will shape the coming years?

Every city has different starting conditions, so there is no one-size-fits-all answer.

My advice would be to start early, gain practical experience, and exchange knowledge with others. There are events such as the annual C-ITS Forum, which places a strong emphasis on collaboration between experts, experienced practitioners, and newcomers.

Cities and operators that engage with C-ITS today, implement pilot projects, and take advantage of available funding opportunities are building a strong foundation for the future.

Over the next few years, I expect V2X to expand beyond individual applications such as public transport prioritization and increasingly connect areas such as rail transportation, traffic management, road safety, and the protection of vulnerable road users.

In my view, connectivity will become a natural and integral part of the transportation system of the future.