Traffic calming, according to the
Institute of Traffic Engineers (
ITE) "involves changes in
street alignment,
installation of barriers, and other physical measures to
reduce traffic speeds and/or
cut-through volumes, in the
interest of
street safety,
livability, and other
public purposes." Traffic calming measures fall into two
broad categories of
volume control and
speed control. Volume control is principally used in
residential areas to reduce the number of
vehicles that will take
shortcuts through the area, speed control is used on major
thoroughfares to reduce the speed. In addition to
engineering efforts, traffic calming can be the result of
enforcement and
education.
The goal of traffic calming is to treat traffic as a fluid, much like a raging river. The individual vehicles and drivers may be annoyed, but the flow is made less turbulent.
The types of calming measures*:
Volume Control
- Full Closure
- Barriers placed across a street to block vehicular traffic. see also: cul-de-sac, dead end
- Half Closure
- A barrier at an intersection to prevent traffic from entering a two-way street.
- Diagonal Diverter
- Barriers placed diagonally across an intersection, Preventing through traffic.
- Median Barrier
- Islands that extend through an intersection, preventing left turns to or from side streets.
- Forced Turn Island
- Islands at an intersection that force traffic to make a right turn, usually when a cross street enters major road.
Speed Control Measures
- Speed Hump
- A rounded, raised area, usually between 3 and 8 meters across.
- Speed Table
- A flat-topped speed hump, usually with a trapezoidal cross-section.
- Raised Crosswalk
- A speed table which is marked as a crosswalk. This has the added benefit of making pedestrians more visible.
- Raised Intersection
- An entire intersection which has been elevated as a speed table, with ramps on all approaches
- Textured Pavement
- Using a textured material such as brick or cobble, which is not only aesthetically pleasing, but uncomfortable to drive over at high speed
- Traffic Circle
- Islands placed in the middle of an intersection, which requires traffic to curve around.
- Roundabout
- Larger versions of traffic circle, also called a rotary.
- Chicane
- Curb extensions, islands, or side-to-side alternating parking patterns which force drivers to travel in an S-shaped path, rather than in a straight line.
- Realigned Intersection
- Intersections that change T-intersections into more curved Y-shaped intersections.
- Neckdown
- Curb extensions at intersections to reduce the number of lanes.
- Center Island
- Street narrowers that remove a chunk from the middle.
- Choker
- Street narrowers that remove chunks from the sides.
*All left and right-handedness terms are for those who drive on the right side of the road.
Reverse the terms if you drive on the
left side.
Sources:
http://www.trafficcalming.org/
http://www.ite.org