July Traffic Calmer

Traffic calming, while popular in Europe for decades, is still in its infancy stages in the US. More and more cities across America have begun installing these devices as a solution to speeding traffic on residential roads. In the past several years, the use of rubber traffic calming devices has escalated dramatically. But what is the difference between the various devices and their applications on local roads? While varying in popularity, speed humps, tables, cushions, bumps, and traffic circles all have their own unique usages and configurations. Here is a brief guide to some of the different types of traffic calming devices and their applications.
Speed Humps: Speed humps are parabolic in shape and used on residential roads to slow cars to between 10 and 20 miles per hour. They are often installed in a series to avoid speeding before and after the hump. Humps are usually placed on residential streets and are not used on major thoroughfares, bus routes, or primary emergency response routes. Ideally, they are installed mid-block between intersections, approximately 200 feet from the intersection with 600 feet between devices. Studies conducted by the Institute of Transportation Engineers found that speed humps, on average, reduced traffic volume by 18% and collisions by 13%. Traffic Logix speed humps are either 3 or 4 inches high and come in lengths of 7 or 14 feet, although they are customizable in 18 inch increments.
Speed Tables: Similar to speed humps, although with long flat-topped centers, speed tables slow cars more gradually. They slow cars to estimated speeds of 20-35 mph. The flat top of a speed table is generally long enough for the entire length of a car to rest on top. This design lets cars drive over the table without slowing down as much as for speed humps or cushions. Speed tables are therefore used on roads with typical residential speed limits. A study conducted by Fehr and Peers of 8 speed table sites found a 45% decrease in accidents per year with the use of speed tables. Traffic Logix speed tables are 3 inches high and come in standard lengths of 10.5, 14 or 21 feet although they are customizable to additional lengths.
Speed Cushions: The newest available traffic calming device, speed cushions (also called speed lumps) are used to slow cars down without affecting emergency vehicles. Speed cushions are used on residential roads to slow cars to approximately 15-25 mph. Designed as several small speed humps, cushions force passenger vehicles to slow down with one or both wheels on the cushion. The split design, however, allows the wider axle of emergency vehicles to straddle speed cushions without delaying their response times. Since speed cushions are a newer device, there are no formal studies documenting their effect. Informal studies indicate that cushions slow cars similar to humps. One Florida community that used Traffic Logix speed cushions reported that the 85th percentile speed was reduced from 38 mph to 26 mph. Traffic Logix speed cushions are 3 inches in height and 7 feet long.		Upcoming Events:
Speed Bumps: Sometimes colloquially used to describe the whole gamut of traffic calming devices, speed bumps are in fact primarily used off the road- in parking lots or alleyways. Speed bumps slow traffic nearly to a halt. Traffic Logix speed bumps are 2 ¼ inches high and 4 or 6 feet long.
Traffic Circles: Placed in the heart of intersections, traffic circles are raised islands that slow cars by forcing them to drive around a circle, thus impeding vehicle speed. The speed to which cars are slowed is dependent on various factors such as the circumference of the circle, and the configuration of the approaching streets. Traffic Logix rubber curbing consists of units of flexible rubber that are bent and installed around a landscaped area.		Don’t miss Craig Timothy’s Traffic Calming Solutions presentation at the APWA show!
When choosing and placing traffic calming devices, it is important to keep in mind the local speed limit, whether emergency response time is a factor, and the effect the devices will have on neighboring streets. For more information about traffic calming devices, visit us online at www.trafficlogix.com or call us at (866)915-6449.		3 Harriett Lane Spring Valley, NY 10977 (866)915-6449 www.trafficlogix.com Contact Us!