Institute of Transportation Studies at UC Berkeley

Transportation investments have historically been among society’s most important contributors to environmental improvement, but today transportation programs and projects are more often of concern as sources of major environmental problems. Over the past thirty years, since the enactment of the National Environmental Protection Act (NEPA) and the first Clean Air Act Amendments (CAAA), the relationship between transportation planning and environmental policy making has continuously become ever more complex and problematic. Until about 1835, when early public transport was just being introduced into many cities, virtually everyone resided within walking distance of where he or she worked, whether on a family farm or in an urban area, and the limited capacities of transportation systems determined that most people traveled very little and experienced tightly bounded environments. By the start of this century, transportation had evolved rapidly from horse carts to horse-drawn omnibuses to street railways, and cities expand dramatically in response to increasing mobility. But cities were still mostly crowded, dirty, dense, congested places, beset by a myriad of environmental problems and limited in size by their transportation systems. The first national conference on City Planning and the Problems of Congestion held in Washington in 1909 was characterized by many speeches in which intellectuals of the day insisted that the environmental challenges of their time -  the disease, poverty, darkness and vice of the North American city -  were caused by the scourge of high-density living, and that it was the job of urban transportation planners to build public transit routes to outlying areas for the explicit purpose of lowering density and improving the living conditions.