Medical and Social Institutions (MSI) and specialized schools for students with disabilities use specialized transport services every day. As a result, paratransit represents one of the main costs for specialized schools and is also expensive for public authorities. We investigate a practical case from France, where these establishments typically have around 80 % of their users benefiting from a specialized transportation service. In this study, the considered MSI and specialized schools (called schools in the remaining of this abstract) are interested in studying the benefits of pooling their transport. The organization of such transport systems requires solving a Dial-a-Ride Problem (DARP) to design the best possible routes for vehicles that pick up their passengers at home and drop them off at their destination, provided they can share part of their route [2]. When several schools have similar start times, it is hard to design feasible routes that can pick up passengers living in the same area and going to separate schools. Hence, modifying the schools’ start times, which is known as School Bell time Adjustment (SBA) in school bus routing [1], facilitates transportation pooling. We address the optimization problem which consists of simultaneously determining the school start times and vehicle routes and denote it the Dial-A-Ride Problem with School Bell time Adjustment (DARP-SBA).