Yearly, 20.000 fatalities are recorded in road accidents on European roads alone. This situation is far more severe (1.3 million humans) when the global scope of road accidents is considered. Thus, Policymakers are initiating policy programs to overcome this challenge by enhancing safety and maximizing the associated positive economic impact. The EU committed to minimizing fatalities by 50% by 2030 and to be net zero long-term by 2050.

To achieve this, vehicular communication networks (VCN) can play a crucial role. It is anticipated that the connectivity and communication of vehicles with their environment contribute to these goals by enabling safety functionalities or improving the traffic flow. Hereby, it is crucial to understand that this communication requires an infrastructure that assists the vehicles and ensures data transmission and operation. However, due to the European size and heterogeneity of the member states, realizing a vehicular communication network on a large scale requires increased coordination and collaboration efforts. Currently, no vehicular communication network has been introduced working EU-wide. Hence, this resembles a potential for future road improvement. To realize this, decision-makers must understand the complex properties and system interrelationships of such a large-scale infrastructure project so that a common VCN can be designed to ensure interoperability and robust functionalities across the EU. This work contributes to the aforementioned challenge by addressing the following research question:

What are fundamental socio-technical factors to consider in a future European vehicular communication network design?

A mixed approach that combines Peffer´s design science research framework and system engineering methodology is used to synthesize the contributions. By this, a vehicular communication network mission, stakeholder, and system analysis are presented in this work. Further novel and scientific sound requirements and stakeholder insights are synthesized by systematically reviewing 57 articles and interviewing 15 experts from the institutional, scientific, and industry domains. In this context, a stakeholder classification for vehicular communication networks, a 4-layer stakeholder complexity model, and a system requirement structure from a system perspective are proposed to contribute to the VCN understanding and future design attempts. Further, the reflection of the socio-technical interrelations between the technical and social VCN subsystems are subjects of this work.

The conclusion is that the reflection on socio-technical system properties plays a critical role in vehicular communication network design. Further, a future vehicular communication network consists of a magnitude of stakeholders with high interest and power; thus, designers must understand the characteristic of their co-evolutionary cooperative development. Hence, a multidisciplinary understanding and approach are critical for designers. Furthermore, the geographical segregation of designing and decision-making in a future vehicular communication network is identified, and certain goals/issues should be addressed in the respective layer. Another major conclusion is that the VCN discussion is determined more by social and socio-technical conditions, such as stakeholder cooperation/coordination and interoperability, than by technical feasibility.
These findings result in three main research contributions, which are summarized as follows:

- A 4-layer stakeholder complexity model contributing to the understanding of VCN development is contributed.
- An approach of integrating the socio-technical system perspective on the complex, large-scale infrastructure VCN project is contributed. This focuses on the processes and requirements between social and technical subsystems, addressing the integration of heterogeneous stakeholder interests.
- A comparison is made between scientific focus, stakeholder needs and objectives, and expert insights, highlighting the mismatch and alignment of requirements. This contributes valuable insights for adjustment and further research in the VCN community.

Further methodological contributions can be concluded:
- The design science research approach is aligned with systems engineering iso standards and methodology.
- The design science research framework is used as an approach to address the complexity of VCN systems. This novel perspective helps VCN stakeholders design solutions for their field problems.

The results have implications for designing stakeholders in a VCN. Based on the analysis, it is recommended that policymakers identify and extend common objectives with the industry to establish public-private business cases. Further, vehicle manufacturers should participate and embrace the transition to a vehicular communication network by cooperating strongly with stakeholders. In addition, implementing the relevant technologies to communicate with the heterogeneous infrastructure is suggested to shape future infrastructure connectivity development. Lastly, the lack of socio-technical reflection in scientific literature is identified. Hence, scholars should elaborate on the interactions and interrelationships between the social and technical subsystems in future work.