This paper describes a framework for evaluating traffic calming programs. It includes a wider range of impacts than are often considered. Potential benefits include road safety, increased comfort and mobility for pedestrians and bicyclists, increased non-motorised travel, reduced traffic noise and air pollution, increased street activity and neighbourhood interaction, and increased property values. Traffic calming can help create more liveable communities and reduce suburban sprawl. Traffic calming costs can include project expenses, vehicle delay, traffic spill over, problems of 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 cost on people who are intensive automobile users. Traffic calming can increase horizontal equity by improving the balance between different users of public streets and reducing the external costs imposed by motor vehicles. Traffic calming tends to increase vertical equity because it benefits most people who are physically, economically and socially disadvantaged, while imposing the greatest disbenefits on relatively wealthy, higher mileage, suburban 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. (Author/publisher)
Abstract