Hradec Králové - a complex C-ITS system        

Our flagship C-ITS project showing almost a full spectrum of C-ITS use-cases in a working and tightly coupled ITS system. C-ITS was not the goal, it was just a tool to improve the city traffic. The project was awarded in C-ROADS Urban C-ITS Contest.

Internationally appreciated showcase of C-ITS        

The project "Intelligent transportation system in Hradec Králové" was done by Czech companies Cross and Herman. In the project we were responsible for the C-ITS part. The goal of the project was to improve efficiency and safety of the traffic in the city. C-ITS as such was not the goal of the project, it was just selected to be the most suitable technology to achieve the goal. Building upon our experience from Brno, we have created a system which achieved a tight integration of all C-ITS parts to the overall ITS system. Thanks to that, the deployment counts as one of the most interesting urban C-ITS installations in Europe.

Project background

The city decided to build a complex intelligent transportation system, which would allow more efficient and safer traffic in the city. Therefore, the following was done in the years of 2020 - 2023:          

• All traffic light controllers were replaced
• New traffic control system was installed
• Smart city platform INVIPO was deployed
• Violation detection system was created
• CCTV ssytem with statistics and alert functionality
• Public transport and emegency vehicle priority
• C-ITS Back office server

Designed to improve life of citizens now

The project was done with the goal of improving the life of the citizens of the city. Therefore, there are use cases whose effect is already visible – priority of public transport and emergency vehicles at intersections. In addition, the system provides use-cases which allow the drivers of connected cars to be better informed.

The complete C-ITS system in Hradec Králové consists of:

• OBUs on public transport vehicles - 130 vehicles (buses, electrobuses and trolleybuses)
• OBUs on road operator vehicles - 7 vehicles (road sweepers, winter maintenance)
• Emergency vehicles - more than 10 (fire brigade, ambulance, municipal police)
• RSUs, connectd to traffic light controller - 40 RSUs
• C-ITS Back office - central system for C-ITS message generation and unit monitoring

We supplied all C-ITS units in the city (except for ambulances) and made them interoperable. In addition, the C-ITS Back office server is our server Anbos.

 Public transport vehicles

In 2022, we equipped about 130 public transport vehicles with OBU units. The OBU takes the trip-related data from the on-board computer (proprietary protocol). Using the same protocol, it provides the on-board computer the status of priority requests. There is an internal configuration of the OBU with a list of intersections plus ingress and egress approches for each stop sequence. By this the OBU is able to request priority in time. The configuration comes from our server Anbos.

Road-side units

In 2022, we supplied 40 RSUs to Cross to be connected to their traffic light controllers (TLC). The RSU is connected to the TLC using Ethernet with PoE. The RSUs have the following tasks:

• Providing public transport priority by SREM+SEEM messages. After receiving the first SREM, the RSU monitors the vehicle position using CAM and SREM messages and informs the TLC accordingly.
• Providing emergency vehicle priority using CAM messages. The RSU monitors the vehicle and triggers priority in the TLC at the right time. As there is route available at the OBU, there is no reason to use SREM messages. Thanks to a complete coverage of all TLCs with emergency priority, the travelling of emergency services is much safer and faster.
• Providing MAPEM and SPATEM information from the TLC to connected vehicles. Currently, all intersection are configured with MAPEM following C-ROADS standards, including node links.
• Distribution of C-ITS messages to and from the C-ITS Back office Anbos. The RSU does not alter the messages, it is able to send the signed messages from the C-ITS BO.In the opposite direction, it sends the received messages from vehicles to the C-ITS BO.

Roadwork vehicles

The 7 road operator vehicles, mainly sweepers and winter maintenance, warn passing drivers by sending either RWW-WM or RWW-RM warnings. The warning is triggered automatically when the lightbar is activated.

C-ITS Back office

The hearth of the C-ITS system in Hradec Králové is our C-ITS Back office system Anbos. It is responsible of two important tasks:

• monitoring, configuration and updates of all connected C-ITS units. 
• generation, signing, verification and processing of C-ITS message.

The Anbos system is connected to the city smart city platform INVIPO by Cross, from which it takes the traffic information which should be converted to C-ITS message. The C-ITS messages are then distributed using MQTT protocol following the results of the project C-MobILE. Such message distribution also allows a fully hybrid communication, where the C-ITS units communicate both directly (via V2X) and also via the C-ITS Back office (latency cca 60 ms). For instance, the SREM request arrives to the RSU both directly and using the C-ITS BO. This helps in making the priority more reliable, as there are intersections where the direct communication is not possible early enough.

Configuration of C-ITS units

The Anbos system allows a complete monitoring and configuration of the units. This means that the following is possible:

• Full OBU settings (e.g., vehicle typeor communication with the board computer).
• Full RSU settings, including its location and complete MAPEM configuration.
• Full communication settings including security, PKI and communication with servers.
• Full IP setting, including IP addresses, APN and routing tables.

System architecture

The deployed system consists of several parts as shown on the figure above. The items in the polygon were delivered in the project:

• INVIPO – top-level traffic management system, also called a smart city platform. It is responsible of collecting all traffic-related events and information. 
• Anbos – C-ITS Back office server, responsible for unit monitoring and configuration. 
• C-ITS Backend – a part of Anbos responsible for C-ITS message generation, signature, reception and processing. 
• RSU – the RSU units typically connected to the traffic light controllers. 
• OBU – the OBU units installed on several types of vehicles. 
• PKI – the units are connected to Czech PKI. 
• BO-to-BO server – this server provides C-ITS messages from other C-ITS BOs in Czechia. 
• Other traffic servers – source of traffic information for INVIPO. 

Note that the C-ITS Back office Anbos communicate with units using two protocols: Protocol I3 – MQTTS-based protocol for message distribution, following the proposal from the C-MobILE project. Protocol I4 – HTTPS-based interface for monitoring and configuration.

Conclusion

In our opinion, the system in Hradec Králové is one of the most interesting C-ITS deployments in Europe. Not only thanks to its completeness, but also thanks to the fact that is was not built as a C-ITS system. C-ITS was just use as the most suitable tool to satisfy the city needs.