City transport system studies have been a constant challenge for engineers and planners all over the world, particularly because their decisions affect people's daily lives. The environmental impacts in urban areas due to traffic play a significant role and it could be considered that nowadays the evaluation of intervening factors in the transport system is based on the examination of their environmental dimension; that is whether the target to upgrade the quality of the environment can be achieved.

New ideas, which are often supported by the evolution of new technologies in the transport sector, have materialized in various cities all over the world where people from different backgrounds and cultures face similar daily problems as far as transportation is concerned. These case studies should benefit all those who are involved in the process of transportation planning and engineering.