The world has entered the urban era. In about thirty years, three-quarters of the world population will live in cities. Yet urban development is not under control and is being achieved in developing countries at the cost of serious socioeconomic and environmental damage. It follows the Western model of urban development, which has become the benchmark for the rest of the world. A strategy of sustainable urban development should start from a radical departure from this model, which is based on a huge waste of resources. This paper focuses on one of source of waste, namely transportation policies. This is analyzed in the with reference to Europe, and it highlights the phenomenon of car dependency and its associated environmental consequences, both local and global. These are: energy consumption, and carbon emissions. Individuals’ psycho-sociological behaviors are confronted with nature’s realities. The widening gap between subjective and objective aspects leads to an ethical questioning, specifically to the need to formulate a problematic of responsibility.