Public transport increasingly requires efforts from a number of actors, each with its own budget and areas of responsibility. Extensive institutional changes are driving factors behind this, where public transport operators along with public organizations are involved in different forms of marketization. This Swedish case studies collaboration between a small town and the region where the question raised is what impact changing institutional conditions and especially public tendering has on their relation. The case points to the provisional character of events and the need for improvisations. Conclusions highlight this experimental character and how looking at the collaboration as a laboratory can prove fruitful. This is suggested to be of value both for the actors to understand their role and for research to identify methods for studying how markets are created in current public transport.