This paper proposes a new intelligent transportation system (ITS) that uses not only integrated cellular and wireless multihop relaying technologies but vehicles' mobility profiles to provide quality yet affordable services as well. It focuses on a subsystem where cellular bandwidth is mostly used for control signals, and a wireless mesh network called ad hoc distribution network (ADN) is used for file transfer in a multihop fashion from one or more server stations to vehicles via access points (APs) using ad hoc channels. A major design goal is to maximize the amount of requested data that can be delivered to the requesting vehicles during their journey using the ADN, taking into consideration the limited coverage of each AP and the requirement that the requested data have to arrive at a certain AP before the requesting vehicles arrive at that AP in order for the data to be downloadable. This paper proves that the optimization problem, as well as its key variations, is NP-hard and proposes efficient solutions to the problem. Analysis and realistic simulations involving a real city map and practical vehicular traces are used to evaluate the performance, and the results indicate that satisfying performance for file download applications can be achieved.