While the relatively free and frequent flow of traffic across international boundaries is an essential foundation of cross-border regions, cross-border public transit systems are the ultimate symbols of metropolitan integration. This paper investigates the governance of the cross-border transit system in Eurometropolis of Lille-Kortrijk-Tournai between France and Belgium. It relies on a qualitative analysis of actors and institutions as well as social network analysis to more precisely fix the positions and roles of actors on either side of the border. The new cross-border institution, the EGTC Agency, is a central actor in public transit policy networks and its function is more complex than the institutional analysis implies. Evaluating these roles in evolving cross-border public transit policy enables an assessment of the effectiveness of this new governance institution and the challenges faced by general-purpose cross-border governance structures in affecting policy areas in which political authority is fragmented.