Making decisions on how to best spend your money on transportation improvements takes a great deal of research, analysis, and consideration of both the short-term benefits and the big picture over time. Transportation programs and projects often serve several different and sometimes competing objectives.
There are always more needs than available funds and it can be difficult to justify making decisions that make sense for the whole transportation system over time, but might not be the best short-term solution.
Sustainability is a concept that gives decision-makers additional information when making difficult choices. This additional information includes the economic, social, and environmental effects of the projects and programs being considered.