# Designing a C-ITS Communication Infrastructure for Traffic Signal Priority of Public Transport
## 5 Conclusions  
With the gradual digitization of mobility, intelligent transport systems are becoming increasingly popular. Likewise, in an effort to standardize public transport prioritization, cooperative intelligent transport systems are being rolled out step by step in Europe and the world. The so-called C-ITS services and applications, in which the increase in efficiency and safety is based on the cooperation itself, are also on the rise across Europe and are enabling automated mobility by combining networking and cooperation/collaboration. This interaction between the participants and/or stakeholders offers additional potential that was previously unavailable, and it can be tapped into and compared to the original definition of the ITS. For the prioritization of public transport, this means that the standard published in May 1980 is about to be superseded. As the underlying frequencies will no longer be available in the near future, the traditional methods of public transport prioritization have to gradually be replaced by new developments, e.g., C-ITS services, as described in this paper. ITS services are essentially already being rolled out. Starting with applications such as hazard warnings on motorways, ITS services are currently being implemented on the infrastructure side in many urban areas. Here, for example, green light optimal speed advisory should be mentioned. Step by step, commercial vehicles are being equipped with the appropriate communication modules/components in order to be able to use and offer a broader spectrum of ITS services. The basic idea of the cooperation between infrastructure--e.g., traffic lights--and vehicles consists of the mutual and continuous exchange of information, improving the quality of the traffic flow as well as increasing traffic safety. In order to be able to exploit the full potential of C-ITS, further development is needed, for example, in the field of traffic light control systems and tooling for applications in public transport. The new control mechanisms differ fundamentally from the current procedures, for example, with regard to the way in which public transport is prioritized. The paradigm shift from today's static registration point procedure to linear and dynamic recording using standardized C-ITS messages opens up completely new perspectives that must be taken into account, as this will also provide continuous support in complying with the norms of regulatory bodies. Consequently, the standardized way of C-ITS communication and harmonization will have a Europe-wide scaling effect on the entire mobility sector. This means that the process is not only driven by transport companies in technical, regulatory, and administrative terms, but also receives support and, above all, impetus from the entire mobility industry. In the future, the entire mobility sector will benefit from the rollout of C-ITS--the networked intelligent transport systems. Conceptualization, T.O., I.P. ; methodology, J.H., M.K.-G.; software, J.H., M.K.-G.; validation, J.H., I.P. ; formal analysis, T.O., I.P. ; investigation, T.O., J.H., LP., M.K.-G., V.I. ; resources, T.O., V.I. ; data curation, I.P., J.H., V.I. ; writing--original draft preparation, T.O., I.P. ; writing--review and editing, all; visualization, J.H., I.P. ; supervision, T.O., V.I. ; project administration, T.O., V.I. ; funding acquisition, T.O., V.I. All authors have read and agreed to the published version of the manuscript. This study was financially supported by the German Federal Ministry for Digital and Transport (funder). Project Frankfurt-MIND. Funding number: 16 DKV42031. Not applicable.