Chapter 7 Transportation on Demand

Publisher Summary Transportation on Demand (TOD) is concerned with the transportation of passengers or goods between specific origins and destinations at the request of users. In recent years, TOD systems have become increasingly popular for a number of reasons. With the aging of the population and the trend toward the development of ambulatory health care services, more and more people rely on door-to-door transportation systems provided by local authorities. Aircraft sharing has also gained in popularity because of the cost reduction efforts made by organizations and the numerous problems that have recently plagued the airline industry. A growing emphasis on electronic commerce, cycle-time compression, and just-in-time deliveries has increased the need for demand-responsive freight transportation systems. TOD systems can be either static or dynamic. In the first case, all requests are known beforehand, while in the second case, requests are received dynamically and vehicle routes must be adjusted in real-time to meet demand. Most TOD problems are characterized by the presence of three often conflicting objectives: maximizing the number of requests served, minimizing operating costs, and minimizing user inconvenience.