Background: Transportation planning practitioners have found it difficult to accurately assess the social and economic effects of transportation investments on communities. This difficulty stems from a lack of available methods, tools, and techniques that are appropriate for the scale, context, and complexity of the project. The result is that planners and decisionmakers have limited information and understanding of the full range of effects that may be attributed to a transportation project's development. This has made it difficult for state DOTs, MPOs, and other agencies to fully meet the intent of requirements for Federal-Aid Highway funding recipients to conduct social and economic analyses of their programs and projects. Title VI of the Civil Rights Act of 1964 and the Federal-Aid Highway Act of 1970 (23 USC 109[h]) provide the basis for requiring these types of impact assessments. In 1991, the Intermodal Surface Transportation Efficiency Act further emphasized the need to address social and economic issues within state and metropolitan planning as well as during project development. In 1994, Executive Order 12898 on environmental justice elevated the emphasis on assessing impacts on minority and low-income populations and communities. In 1996, the Federal Highway Administration (FHWA), with the support of the American Association of State Highway and Transportation Officials (AASHTO), published a Community Impact Assessment reference booklet that describes steps for, and emphasizes the importance of, evaluating community impacts within the FHWA process for meeting the requirements of the National Environmental Policy Act (NEPA).

In order for the states and MPOs to more effectively meet federal requirements, a need existed to identify methods, tools, and techniques that will aid practitioners in assessing the social and economic implications of transportation projects for their surrounding communities.

Objective: The objective of this research project was to develop a guidebook that identifies, describes, and evaluates existing methods, tools, and techniques that will aid practitioners in assessing the social and economic effects (positive and negative) of transportation projects. The social and economic effects included primary, secondary, and cumulative effects on the following: community cohesion; mobility; safety; accessibility; aesthetics; relocation; employment; community facilities; land use; property values; construction effects; and previous actions intended to mitigate adverse project impacts. The purpose of the handbook is to help practitioners satisfy NEPA and other requirements for consideration of social and economic effects of transportation projects. Appropriate analytical detail was provided for different phases of project planning, development, and implementation.

Tasks: The research objectives were accomplished through the following tasks: (1) Conduct a search for existing or prospective methods, tools, and techniques that may be suitable for estimating the social and economic effects of transportation projects. (2) Conduct a survey to determine what methods, tools, and techniques are currently employed by federal agencies, states, MPOs, transit agencies, and local jurisdictions to estimate the social and economic effects of transportation projects. Prepare a technical memorandum for panel review summarizing the results of Tasks 1 and 2. Include in the technical memorandum an annotated bibliography of all sources. (3) Establish a classification system of the existing methods, tools, and techniques. The system should record areas of current application, data required, outputs produced, algorithms and processes employed, and areas of potential application. The research may include other attributes that the researcher determines are essential to support the Task 4 evaluation. The researcher should catalog the methods, tools, and techniques in accordance with this system. (4) Perform a critical evaluation of the classified methods, tools, and techniques. The researcher should assess and document the advantages and disadvantages of each method, tool, and technique for use in estimating the social or economic effects of transportation projects in each phase of project planning, development, and implementation. Identify important gaps and research needs. (5) Prepare an interim report summarizing Tasks 1 through 4 and include a detailed outline for the handbook to be developed in Task 6. Present findings and the outline to the panel members for approval before proceeding to Task 6. (6) Prepare an initial draft of a handbook of current practices and applications for practitioners. Recommend those methods, tools, and techniques that should be employed in each phase of project planning, development, and implementation. Submit the draft handbook for panel review. (7) Conduct focus group sessions during various transportation organization meetings (e.g., AASHTO and Association of Metropolitan Planning Organizations), to obtain feedback on the content of the draft handbook and information on gaps and additional research needs. Prepare a technical memorandum summarizing the results of the focus group sessions and discuss the results with the panel in a teleconference. (8) Based on panel input, prepare a final report and handbook that reflect the research findings, identify gaps and research needs, suggest sources of information, and provide guidance to practitioners for conducting accurate assessments of economic and social effects associated with transportation projects.

The resulting guidebook identifies and describes best current methods for assessing the impacts of new projects in the following areas: travel time, safety, vehicle operating costs, choice of mode, accessibility, community cohesion, economic development, traffic noise, visual quality, and property values. The guidebook also includes a discussion of distributed effects: how the various positive and negative impacts are experienced by different subgroups within the community.

The guidebook will be particularly useful for conducting assessments and producing results that are easily understood by residents, stakeholders, and decision-makers. It will help planners not only to comply with applicable laws, executive orders, and regulations, but also to employ best practices for good participatory planning.

Status: The project is complete.

Product Availability: The final report is published as NCHRP Report 456.The contractor's final report is posted in pdf (portable document format) as NCHRP Web Document 31.