Considering the environment in transportation planning: Review of emerging paradigms and practice in the United States

Several state Departments of Transportation (DOTs) and metropolitan planning organizations (MPOs) in the United States are considering environmental issues in the early stages of the transportation planning process, recognizing that there are benefits to be gained from better decisions, reduced public controversy, and shortened times to project implementation. This paper examines the current practice of such consideration, with special emphasis on best case examples. The study was conducted through a literature review, a survey of state DOTs and MPOs, and the identification of best case examples. The findings indicate the emergence, both in the literature and in practice, of more formal recognition of the need to consider environmental factors earlier in the planning process. State DOTs and MPOs agree that air quality, land use, socio-economic, environmental justice, and community cohesion impacts are of greatest concern today, and will be so in 10 years. Different approaches for considering environmental factors in planning include scenario analysis, environmental analysis of plans, environmental performance measures, consideration of equity issues, new data and analysis tools, and innovative institutional partnerships.