Definitions of traffic calming vary, but they all share the goal of reducing vehicle speeds, improving safety, and enhancing quality of life. Some include all three “Es,” traffic education, enforcement, and engineering. Most definitions focus on engineering measures to change driver behavior. Some focus on engineering measures that compel drivers to slow down, excluding those that use barriers to divert traffic. The following are some example definitions.
Institute of Transportation Engineers – Traffic calming involves changes in street alignment, installation of barriers, and other physical measures to reduce traffic speeds and/or cut-through volumes, in the interest of street safety, livability, and other public purposes.
Transportation Association of Canada – Traffic calming involves altering of motorist behaviour on a street or on a street network. It also includes traffic management, which involves changing traffic routes or flows within a neighbourhood.
Montgomery County, Maryland – Traffic calming consists of operational measures such as enhanced police enforcement, speed displays, and a community speed watch program, as well as such physical measures as edgelines, chokers, chicanes, traffic circles, and (for the past four years) speed humps and raised crosswalks.