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 openess. 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.