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Traffic-Calming
Measures
A busy intersection, an endless traffic jam, pedestrian crosswalks that self activate, an impatient driver whose daycare closes in 10 minutes and sees, on the right, an innocent and defenseless little neighborhood street. Our driver sharply turns into this shortcut, this unexpected way out (which will subsequently become an acquired right!), simply to save a precious minute but without ever realizing the danger of such a maneuver, nor the fact that he almost ran into little Timmy there, on his bicycle... Does this scenario sound familiar? This phenomenon is on the rise in our communities and is not about to go away. First appearing in the nineteen-forty's and fifty's in the United States, and in the late sixties in Europe, the principles of traffic-calming are now becoming more and more used in residential traffic management. Two major problems can be attenuated using traffic-calming measures, and these are speed and traffic flow.
The speed bump is probably the best known control device and can bring favorable results if used properly. In order to make the system as effective as possible, the distance between speed bumps must be properly adjusted. Placed too far apart, for example, allows motorists to increase their speed between each bump, diminishing expected results. Certain conditions, such as lighting or the slope of the street, must be considered before proceeding with the installation of such a device. The curb extension (neckdown) is another means of modifying the driver's visual field, making it uncomfortable for him to speed. Generally, curb extensions are found at pedestrian crossings and are adorned with floral arrangement and site furnishings (urban furniture). For a very wide street, a traffic island can be placed on the center line. This device decreases the street's width and at the same time, the motorist's field of vision. This narrowing effect encourages the motorist to reduce his speed. There are many other methods of calming traffic. What is important to keep in mind is that to encourage a driver to slow down, we must play on his perception of safety. Traffic flow In order to have some control over the flow of traffic, it is necessary to resort, almost exclusively, to physical means. Depending on the nature of the problem, a whole range of scenarios is available to administrators. "Half closing" a street forces users to use one end or the other. The installation of a traffic island that covers one half of a curb extension creates a physical barrier that prohibits movement in one direction and only for a short distance. This makes it possible to maintain both directions on the street and is more practical for the residents. This method generally affects the flow of traffic only one way. Complete closure has a drastic effect on the volume of circulation since the implied street becomes more or less a dead end. Furthermore, this can create major problems for residents and can, in some cases, have a significant impact on emergency services. An interesting alternative is without a doubt the diagonal diverter which makes it possible to neutralize transitory circulation while keeping the street open and in both directions. In certain cases, this device can have as large an impact on volume as completely closing the road but without the inherent disadvantages. In the final analysis, no matter what device is chosen to reduce the volume of circulation, the real impact depends on the availability and the quality of alternate roads. This applies to the methods directed at the two types of problems mentioned above. The above was a brief overview of the methods available to calm traffic. Although there are a multitude of ways to influence speeds and traffic flow, it is important to keep in mind that each situation is unique and deserves a thorough study of the sector before choosing a solution. Often a combination of several methods can help to solve a recurring problem of circulation. To learn more, visit the Institute of Transportation Engineers (ITE) website at the following address: http://www.ite.org
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Speeding
