Traffic Calming Benefits, Costs and Equity Impacts

This paper describes a framework for evaluating traffic calming programs. Potential benefits include road safety, increased comfort and mobility for non-motorized travel, reduced environmental impacts, increased neighborhood interaction, and increased property values. Traffic calming can help create more livable communities and reduce suburban sprawl. Traffic calming costs can include project expenses, liability claims, vehicle delay, traffic spillover, problems for emergency and service vehicles, driver frustration, and problems for bicyclists and visually impaired pedestrians. Traffic calming tends to provide the greatest benefits to pedestrians, bicyclists and local residents, while imposing the greatest costs on motorists who drive intensively (i.e., as fast as possible). Traffic calming tends to increase horizontal equity by reducing the external costs imposed by motor vehicles and improving the balance between different uses of public streets. Traffic calming tends to increase vertical equity because it benefits people who are physically, economically and socially disadvantaged, while imposing the greatest disbenefits on relatively wealthy, higher mileage drivers. Each traffic calming project is unique, so each project should be evaluated individually. It is important to avoid double counting. Sensitivity analysis can be used to test whether conclusions are reliable under a range of possible scenarios. Traffic Calming Benefits, Costs and Equity Impacts