Comparing Route Deviation Bus Operation with Respect to Dial-a-Ride Service for a Low-Demand Residential Area

Flexible transit services, such as Route Deviation Bus, or RDB, match the features of fixed-haul traditional transit and demand-responsive service. They have been proven to be efficient on the grounds of both cost and performance in many low-density residential areas. This paper deals with a special form of advanced public transport operations, which is known by different names, such as route deviation line, point deviation bus line, corridor deviation line and checkpoint diala- ride. We present the results of a design analysis performed on a real network using a model proposed for the Route Deviation Bus problem, which is based on mixed integer linear programming. The study network is located in Campi Bisenzio, a small town in the surroundings of Florence (Italy). This urban area is characterized by a low level of the transit demand for the major part of the day. Two decades ago, the traditional line-haul system has been replaced with a mixed advance request and immediate request Dial-a-Ride system. In this paper, first, the RDB problem is briefly summarized. Second, the model is applied to the real case of Campi Bisenzio and the results drawn from the model application are shown in comparison with the existing on-demand service management as a mixed operations Dial-a-Ride system. We simulated the RDB service operating in the actual scenario and then we compared the two different operations modes, calculating their respective values in a set of performance indexes. In such a study case, the existing mixed Dial-a-Ride operations mode results are better than the switching to a route deviation bus service. However, this result seems to be highly influenced by the particular frame of the underlying street network. Nevertheless, we can view the obtained results as a meaningful trial performed on a real scale that highlights boundaries and better defines the application domain of the more frequently applied new RDB service operations for the low transit demand management. Finally, our results show that a route deviation strategy is more suitable to accommodate rejected requests, that is, those for which it is impossible to schedule the call, than any Dial-a-Ride strategy