It is difficult to have gangways between coupled units and still retain an aerodynamic leading front end. Because of this, there is usually no passage between high-speed coupled units. This may require more crew members, so that ticket inspectors, for example, can be present in all of them. This leads to higher operating costs and lower use of crew resources. In a locomotive-hauled train, one crew can serve the train regardless of the number of cars in the train provided limits of individual workload are not exceeded. Likewise, in such instances, buffet cars and other shared passenger facilities may need to be duplicated in each unit, reducing efficiency.