ABSTRACT
The concept of "sustainability" is gaining widespread popularity in transportation policy circles around the world. As initially defmed by the Bruntland Commission, sustainability is "ensuring that the needs of the present are met without compromising the ability of future generations to meet their needs" (World Commission on Environment and Development 1987). Subsequent definitions center around the need to satisfy three requirements: improve standards of living, enhance quality of life and ensure an equitable distribution of benefits. In other words, development policies, including those in the transport sector, should simultaneously promote economic, environmental and social or distributional sustainability.
