This book contains 41 papers presented at the Third International Conference on Urban Transport and the Environment for the 21st Century, which was held in Perusta, Italy, September 23-25, 1997. The conference brought together engineers, scientists and managers working in industry, research organizations and government on the development of new technologies, planning and management of urban transportation systems. The meeting addressed the varied problems of urban transportation. It covered different types of transportation systems, such as roads, light railways, and waterways facilities, with particular emphasis on integrating and optimizing the interaction of different systems. The meeting provided an opportunity for the various people working on urban transportation studies to exchange information. The papers cover urban transport systems, environmental studies, planning, funding and management, vehicles and transport technology, transport modeling, traffic studies, and future vision.