Ensuring Sustainability Through Mass Transit

In industrialized countries, the process of urbanization has been largely completed, and the majority of population lives in urbanized areas. In developing countries, the same trend of population shift from rural to urban areas is still continuing. The resulting rapid growth of cities in recent decades has created problems of providing utilities and services, as well as maintaining satisfactory quality of life. The pressures of population growth on physical and environmental conditions in cities is one of the challenges of our urbanized civilization. Consequently, living conditions in cities affect the majority of population, as well as each country's economic prosperity. Experiences from recent decades show that a basic requirement for quality of life in cities, including economic, social and environmental conditions, depends on their sustainability, i.e., trends that provide for stable conditions in the future. To examine the conditions in cities and the role of transportation in them, it is useful to start with a view from a distance and considering the function of cities in society and the elements that affect their efficiency.