Skip to content

Design Guide

Speed Reduction Mechanisms


Cities can achieve a reduction in traffic speeds using a variety of traffic calming techniques. While certain speed controls alter the configuration of a roadway, others change how people psychologically perceive and respond to a street. Consider the following tools to encourage motorists to drive at target speeds.

Median

Medians create a pinchpoint for traffic in the center of the roadway and can reduce pedestrian crossing distances.

Pinchpoint

Chokers or pinchpoints restrict motorists from operating at high speeds on local streets and significantly expand the sidewalk realm for pedestrians.

Chicane

Chicanes slow drivers by alternating parking or curb extensions along the corridor.

Lane Shift

A lane shift horizontally deflects a vehicle and may be designed with striping, curb extensions, or parking.

Speed Hump

Speed humps vertically deflect vehicles and may be combined with a midblock crosswalk.

2-Way Street

2-way streets, especially those with narrower profiles, encourage motorists to be more cautious and wary of oncoming traffic.

Roundabout

Roundabouts reduce traffic speeds at intersections by requiring motorists to move with caution through conflict points.

Diverter

A traffic diverter breaks up the street grid while maintaining permeability for pedestrians and bicyclists.

Signal Progression

Signals timed to a street’s target speed can create lower speeds along a corridor.

Building Lines

A dense built environment with no significant setbacks constrains sightlines, making drivers more alert and aware of their surroundings.

Street Trees

Trees narrow a driver’s visual field and create rhythm along the street.

On-Street Parking

On-street parking narrows the street and slows traffic by creating friction for moving vehicles.