The paper reviews the development of urban public transit over the 20th century. The trends from the last decades are used to forecast the direction of transit and its likely role in the new century. During the early decades of the 20th century rapid urban growth and revolutionary inventions in transportation technology made electric rail transit a major factor in the shaping and functioning of cities. The invention of buses, trolleybuses, automated systems and other modes followed later creating a family of transit modes. The proliferation of the private car led to restructuring of cities and a decreased role for transit, particularly in outlying areas. Increased traffic congestion and environmental concerns, however, increased the need for high-performance transit with separate rights-of-way, which is competitive with the car. Recent innovations in bus technology and services are likely to provide greater diversity and better services in the future. Regular buses will be increasingly complemented by minibuses for specialized services. On the other end of the range will be further applications of articulated buses on bus lanes and busways. Spurred by international commitments for reduced air pollution (the Rio de Janeiro and Kyoto Conferences), alternative fuels and propulsion systems for buses will become common. The period of extensive construction of metro systems which has been under way during the last four decades, will continue as cities grow and street congestion worsens further. Even more intensive will be construction of Light Rail Transit systems. This mode has been developed by upgrading conventional streetcar (tramway) systems as well as constructing new, high performance systems. Dozens of light rail systems have been built in recent years and additional ones are being planned in North America and worldwide. Automated Guided Systems will be built in some medium-sized cities. Further intensification of development and innovations are also expected to continue in regional/commuter rail systems especially through the introduction of new vehicle concepts and train control strategies. This will provide enhanced transit services for expanding metropolitan regions. Computer technology will continue to drive many transit innovations from monitoring and control of buses on streets to fully automated rail transit operations and efficient fare collection. The future role of transit will be defined for different categories of cities by size and character, and be different in developed and developing countries. Emphasis will be made of the strong relationship between the livability, quality of life and social character of cities and the composition of their travel modes: car, transit, pedestrian and others. The importance of public policies in determining transit's role will be discussed. Most European countries have policies favoring transit. In the United States, increased emphasis on intermodalism in federal legislation gives transit good treatment; and the United Kingdom has reversed its anti-transit orientation of the 1980's. Developing countries are also putting more emphasis on developing high-capacity, high-performance transit as their cities grow much more rapidly than those in developed countries and congestion hobbles their economies.