1120 SW Fifth Ave, Suite 800, Portland, OR 97204
A power point introduction to traffic calming devices
Information on Portland speed bumps from the Bureau of Traffic Management Traffic Manual, 1994
Raised cross walks are cross walks constructed 3-4 inches above the elevation of the street.
Curb extensions narrow the street by widening the sidewalk or the landscaped parking strip.
Pedestrian refuges or slow points are small islands in the middle of the street, typically designed with marked bike lanes on both sides.
Choke Points are curb extensions placed mid block to narrow the roadway to 14' or the equivalent of one travel lane.
Exclusion lanes are lanes for a particular class of vehicle, excluding all others.
Cul-de-Sacs close one end of a street.
A median barrier is a concrete curb or island that is located on the centerline of a street and continues through the street's intersection with a given cross street.
Semi-diverters are curb extensions or islands that block one lane of the street.
Diagonal diverters place a barrier diagonally across an intersection, disconnecting the legs of the intersection.
Entrance treatments consist of physical and textural changes to streets and are located at key entry ways into a neighborhood
A chicane changes a street's path from straight to serpentine
Traffic circles are raised islands placed in an intersection
Speed bumps are asphalt mounds constructed on streets and spaced 300 to 600 feet apart
School Improvements PHOTOS
Pedestrian Improvements PHOTOS
Traffic Circle PHOTOS
Traffic Volume Reduction PHOTOS
Rubber Speed Bumps PHOTOS