This paper examines inter-institutional cooperative challenges in the context of implementing the digital road. Five supranational experts from industry, research, and road traffic were interviewed about existing cooperative challenges and how they can be solved. The interviews were analyzed using the grounded theory method. The theoretically developed challenges of complexity, trust, transparency, synchronization, information asymmetries, and conflicts of interest were confirmed and supplemented by the identification of institutions and roles, error culture, and power. According to the experts, these challenges can be overcome by using a strategic tool such as the Institutional Role Model. This tool can be used to involve all actors. In addition, transparency and trust are strengthened by clear role definitions and assignments. Furthermore, the tool ensures the completeness of the actors, improves inter-institutional communication, and identifies the potential for conflict. Therefore, the authors recommend the use of the Institutional Role Model as a steering instrument in complex projects.