We enable the use of V2X

Traffic Light preemption with V2X

Vehicle-to-Everything (V2X) communication is revolutionising the interaction between vehicles and between vehicles and infrastructure. One key area of application is traffic light preemption.

Conventional traffic light preemption speeds up public transport, making it more punctual and attractive. This allows for higher mileage per vehicle and saves costs. V2X further leads to significant energy savings and reduces disruptive stops.

ebblo sees great potential in the use of V2X in public transport and is striving to implement further projects. The V2X vehicle equipment (OBUs) from third-party providers are connected to our on-board computer via an MQTT-based interface (PTX) in order to conceal the high complexity of the V2X air interface from the public transport world.

We are convinced that the integration of V2X will make a significant contribution to the efficiency, safety and sustainability of public transport. Together with our customers and partners, we are shaping the future of public transport.

Advantages of traffic light preemption with V2X

Bidirectional communication: Conventional systems are based on pre-supplied reporting point chains. When a reporting point is reached, the vehicle sends a unidirectional prioritisation request to the traffic light control computer. In contrast, V2X enables bidirectional communication between vehicles and traffic lights. Among other things, vehicles receive information about traffic light phases.
Energy-optimised approach: Vehicles are informed of the next green phase at an early stage. Drivers can adjust their speed to reach the intersection in time for the green phase and continue driving without stopping.
Time-optimised departure: Thanks to timely information about the start of the next green phase, drivers can deactivate the door release at the right moment. The vehicle can depart later and the doors can remain open longer to allow passengers to board.
Flexible path dispatch: V2X technology allows for flexible path dispatch, as paths are no longer stored statically in the junction controller. This increases efficiency and flexibility in operations.

Link to V2X brochure

PTX: Open industry standard for V2X

The PTX specification version 2.0 is the first open, manufacturer-neutral interface for communication between on-board computers and V2X OBUs in public transport. It enables transport companies to integrate V2X functions such as traffic light preemption, green waves and safety warnings in a future-proof, flexible and cost-efficient manner. The PTX specification encourages innovation and competition, reduces integration efforts and creates genuine freedom of choice when selecting OBUs.

The specification is openly accessible and can be used directly in projects. All relevant documents and schemas can be found on the official GitHub page:

GitHub – PTX Interface Specification/ptx-specification: Interface between C-ITS On-Board Units (OBU) and ITCS On-Board Computers (IBIS) – released specification versions including Protobuf and JSON schemas

Link to GitHub Link to PTX News

Traffic light preemption with V2X explained simply

What is V2X-based traffic signal preemption?

V2X enables communication between vehicles and infrastructure. In traffic signal preemption scenarios, vehicles and signal systems exchange information to improve operational efficiency and traffic flow.

How can V2X improve public transport performance?

The technology can help reduce unnecessary stops, improve punctuality and support more efficient vehicle operations. Early information about traffic signal phases allows better driving strategies.

Does V2X support energy savings?

Yes. Vehicles can adjust their speed according to upcoming green phases and avoid unnecessary braking and acceleration. This contributes to more energy-efficient operation.

Can third-party onboard units be connected?

Yes. Third-party V2X onboard units can be integrated through an MQTT-based PTX interface connected to the onboard computer.

What is the PTX specification?

PTX 2.0 provides an open and vendor-neutral interface between public transport onboard computers and V2X onboard units. It supports flexible and future-proof V2X integration.

Which use cases are supported?

Examples mentioned include traffic signal preemption, green-wave functionality and safety-related warnings.

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