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.
They did some traffic crippling. Now only bikes can go down this road.