Transportation decision-making : a guide to social and environmental considerations.

An integrated approach is presented for systematically incorporating social, economic, and environmental factors into transportation planning and decision making. The timely identification is stressed of the nature, magnitude, and incidence of these potential factors so that in all phases of transportation planning, alternatives may be developed that avoid or minimize adverse effects and that take full advantage of opportunities to increase benefits. The early, effective, knowledgeable involvement of the public to clarify issues and to aid in the development and evaluation of proposals in emphasized, and the effective use is stressed of expertise and resources both of the transportation agency and of other agencies with maximum flexibility and openness. The report also stresses the consideration of a range of transportation improvements involving various types of highway facilities, other models, transportation regulations, controls and constraints, and the no-build option. A systematic evaluation process, and the documentation of work performed and decisions made are crucial, and institutional arrangements and decision-making are important. The planning approach and techniques presented here are based on the following findings: the overall process through which social, economic and environmental considerations are brought into transportation planning and decision-making is as important as the particular techniques used for predicting impacts; issues of social equity must be explicitly recognized and taken into account in transportation decision-making; different groups can be expected to have different interest and different priorities. System plans should be defined using a strategy of implementation decisions being made over a period of time, thereby enabling options to be kept open longer. Periodic reassessment of decisions should be built into all stages of system studies. Objectives for all phases of a transportation planning and design process are listed, a 4-phase study strategy is proposed, and the roles of the transportation professional are reviewed.