Complete streets are those designed not only for private vehicles, but also to enable safe access for all users, including pedestrians, bicyclists, motorists, and transit riders of all ages and abilities. Specific street designs vary based on the type of street. Complete streets are intended to improve non-motorized travel safety, reduce costs and environmental burdens, and create more livable, sustainable, and economically vibrant communities. Investment in complete streets projects is growing around the country with these goals in mind. However, there are limited data to verify the effectiveness of complete streets, and the indicators required for quantification of complete street performance are not yet agreed upon. Complete street sustainability indicators are important to assess whether a complete street conversion is achieving its goals and to support decision-making for complete street investment.
Researchers at the University of California, Davis and JCH Research used life cycle assessment, a modeling tool for evaluating a product or activity’s environmental impacts through all stages of its life, to quantify the environmental performance of complete streets. The researchers also reviewed the academic literature for social impact indicators, which have generally not been well developed in life cycle assessment applications. The researchers adapted these indicators to better consider equity, guided by interviews with a diverse set of stakeholders. Complete street typologies compiled from several sources were used to test and refine the life cycle assessment framework for complete street conversions. This policy brief summarizes the findings from that research.