This guide was written as a quick primer for transportation professionals and analysts who assess the impacts of proposed transportation actions on communities. It outlines the community impact assessment process, highlights critical areas that must be examined, identifies basic tools and information sources, and stimulates the thought-process related to individual projects. In the past, the consequences of transportation investments on communities have often been ignored or introduced near the end of a planning process, reducing them to reactive considerations at best. The goals of this primer are to increase awareness of the effects of transportation actions on the human environment and emphasize that community impacts deserve serious attention in project planning and development-attention comparable to that given the natural environment. Finally, this guide is intended to provide some tips for facilitating public involvement in the decision making process.