...a preliminary overview of engineering and environmental impact studies completed for the central area of Boston's proposed Central Artery project and is the basis for detailed future engineering, environmental and related studies; describes the central area in terms of existing facilities, system characteristics, traffic characteristics, and environmental conditions; presents alternatives for improvement; nine construction options are described and evaluated and seven are proposed for further study; discusses the role of citizen participation in the planning process; includes recommendations; an appendix provides material to back-up the approach and methods used in analyzing benefits, impacts and costs of alternatives; a 1977 edition is also kept on this number; copies of these were in the BRA collection