A flexible-route transportation system, primarily utilizing privately-owned vehicles to provide ridesharing transportation for the public, is described. Interactive communications terminals are provided through which drivers of the vehicles may rapidly transmit ride offers via a telecommunications network to a central operations coordinating station, equipped with a general-purpose programmable computer. Rider interactive communications terminals, located at public and private facilities, are also connected by the telecommunications network with the central coordinating station, permitting eligible members of the public to quickly request rides from one location to another. The central coordinating station matches the ride requests with the ride offers, on a trip-by-trip basis, comparing the driver's indicated origin, destination, seating requirements and time with the rider's requested origin, destination, seat availability and time. If a ride offer and ride request can be matched within reasonable limits of space and time, the central coordinating station transmits to the driver the rider's identity and location and transmits to the rider the description and identity of the vehicle, so that the driver can pick up and drop off the rider en route to his or her destination. The system includes security features for preventing unauthorized access to the system by either drivers or riders, accounting features for properly billing riders and reimbursing vehicle owners for transportation services, and special terminals for entering trip information quickly and accurately.