SAFE DESIGN OF PERSONAL RAPID-TRANSIT SYSTEMS

Safety issues have been a primary concern in the development of personal rapid transit since it started several decades ago. Safe design involves careful attention to all features of the design, such as the use of a hierarchy of fault-tolerant redundant control systems, bi-stable fail-safe switching, alternative power supplies, vehicle and passenger protection, and attention to the interaction of people with the system. Safety, together with reliability and adequate capacity, must be achieved while still making the system economically attractive, hence techniques to achieve these goals at minimum life-cycle cost are primary in PRT design. Building on theory of safe, reliable, and cost-effective design of PRT systems developed during the 1970s, in 1981 the author and his colleagues initiated design of a new PRT system, now called Taxi 2000. The paper describes the new design and reviews the principles of safe design, incorporated into Taxi 2000, which he believes will make this new system safer, more dependable, and more economical than existing modes of urban transportation.