Changes in technology, particularly information technology, are having an increasing impact on transportation systems and how we travel. Many automobile manufacturers now install car navigation systems. Personal communications service (PCS, or cell phones) and personal digital assistants (PDAs) affect urban locational and travel behavior. Location-based systems (LBS) will soon be able to use a combination of such technologies to advise travelers of the best route from point A to point B. Using PCS and PDAs, location-based systems will guide travelers to geographic locations, restaurants, gas stations, museums, and other objectives. Information technology also affects us in that any one or more of these telecommunication means may be substituted for face-to-face contact, making travel unnecessary in some cases.