Transportation and mobility lies between the most important critical issues in sustainability, beside others as energy and climate, urban systems, waste management or the public policy. Reaching a sustainable transport system is not just a matter of developing and adopting a number of technological innovations. A broader structural and societal transition is needed in technology, economy, culture, behavioural patterns and institutions. Cluj-Napoca is the largest city in Transylvania, a city that faced a tremendous economic growth after 1990, accompanied by a substantial increase in population in its surrounding area and leading to a rapid and substantial increase in demand for municipal services as well as supporting infrastructure. The rapid rate of motorization experienced in Cluj-Napoca region and its associated problems of congestion and environmental pollution made it an excellent case study in policy formulation and planning for sustainable transportation. The central idea of this article is that policies promoting transportation mobility, economic development and environmental sustainability can be pursued in harmony with one another, rather than as conflicting goals. In particular, it explores how issues of transportation and environmental sustainability could interact in the context of the studied metropolitan area, in which the rate of growth in population and economic development seem to have outpaced the needed transportation infrastructure. The article aims in identifying, given the reality of this supply constraint, the most appropriate ways to manage transportation demand to reduce the immediate pressure on transportation supply and to accommodate the time needed to replenish or expand the existing supply.