This book identifies issues relevant to the debate over the role of the environmental review process in transportation project delivery. It identifies social and environmental issues that led Congress to enact the range of requirements that now make up the environmental review process, as well as selected requirements applicable to its implementation. Also discussed are the complexities in tying the environmental review process to federal-aid highway project delivery time. Issues that make it difficult to determine the time it takes to complete the project development, in general or individual stages of development (e.g., activities related explicitly to environmental reviews); or to identify root causes of project delays tied to specific elements of the environmental review process, are also explored.