When civil engineers and city planners talk about "traffic calming" they're really talking about "traffic crippling." Traffic crippling takes a flow of traffic. Rather than help motorists get from A-to-B as quickly as possible and leave the flow of traffic, they instead cripple the flow of traffic and frustrate motorists into
using alternative travel means (e.g. a bus). Traffic cripplers encourage air pollution by extending the period of any trip and raising the amount of pollutants created by any one motorist.