Assessing the Effects of Highway-Widening Improvements on Urban and SuburbanAreas: A Synthesis of Highway Practice

摘要

This synthesis presents a review of current practices by state and metropolitangovernment agencies for assessing the impacts of highway-widening projects in urban and suburban areas. This synthesis will be of interest to highway environmental specialist (particularly those concerned with assessing social and economic impacts), design engineers, planners, utility managers, and others responsible for the planning, design, and implementation of highway-widening improvements. Information is presented on the reasons for highway-widening projects, the nature of the projects, and the methods and practices for application of analytical techniques used to measure the potential or actual impacts of the projects on people and the physical environment. Mitigation measures are also discussed. This report of the Transportation Research Board describes the most recent widening projects as reported by states or other transportation agencies, as well as the most frequently encountered issues in highway widening. Selected examples of widening projects are included, as in some recognition of the need for additional information and research in the areas of social and economic impact measurement.