Traffic Calming Techniques

In residential neighborhoods where the speed and volume of vehicle traffic frequently conflict with pedestrians and bicyclists, communities may choose to use street design techniques that slow and control the flow of automobile traffic. The intention is to improve the quality of life in neighborhoods and to make them more pedestrian friendly by slowing or discouraging traffic. Traffic calming features need to be designed to fit specific areas, taking into account such information as the road’s cross-section, traffic volumes, adjacent land uses, and distances between origins and destinations. Successful implementation of an effective traffic calming program requires that it be well coordinated and include significant community participation in the decisionmaking process.

Examples of traffic calming techniques include: landscaped curb bump outs to help reduce traffic speeds and the distance required for a pedestrian to cross a roadway; narrow streets; street islands and marked, signalized crossings to enhance pedestrian safety; street trees; and speed humps. Of course, another non-physical technique to slow down drivers is to set speed limits of 20-25 mph in downtown areas, historic neighborhoods, parks, school zones, and waterfront areas.

Below are specific definitions of several traffic calming techniques:
Chicanes - Physical obstacles or parking bays, staggered on alternate sides of the highway so that the route for vehicles is winding.

Curb Extensions (sidewalk widening) - The sidewalk on one or both sides of the road is extended to reduce the highway to a single lane or minimum width for two-lane traffic. This reduces crossing distances and discourages parking close to intersections and crosswalks.

Mini-Roundabouts (traffic circles) - Small roundabouts situated at an intersection. Some have raised centers, landscaping and other features, while others are just painted circles on the road.

Raised Intersections - The highway is raised at an intersection, usually by brickwork or a plateau with a ramp on each approach. The platform is at curb level and may well have distinctive surfacing.