Paratransit challenges the conventional approach to public transport in the United States, which depends on fixed-route, fixed-schedule, publicly owned or regulated systems such as buses and trains. Paratransit is a type of service which relies on small vehicles which are frequently privately owned and operated, and which may not work on a schedule. The various options concerning service types, market niches, and effectiveness are discussed, along with the future of paratransit. Case studies describe paratransit systems in the U.S. and other places, and the interaction of paratransit with more traditional systems.