Bicycle Safety Guide and Countermeasure Selection System
An example of a chicane created through landscaped islands in Tallahassee, Florida. http://www.pedbikeimages.org/ - Dan Burden
Chicanes create a horizontal diversion of traffic and can be gentler or more restrictive depending on the design.
Diverting the Path of Travel
Shifting a travel lane has an effect on speeds as long as the taper is not so gradual that motorists can maintain speeds. For traffic calming, the taper lengths may be as much as half of what is suggested in traditional highway engineering. The taper lengths should reflect the desired speed, which should be posted prior to the chicane.
Shifts in travelways can be created by shifting parking from one side to the other (if there is only space for one side of parking) or by building landscaped islands (islands can also effectively supplement the parking shift).
Diversion Plus Lane Restriction (Angled Slow Points)
Diverting the path of travel plus restricting the lanes (often called chokers) usually consists of a series of curb extensions, narrowing the street to two narrow lanes, or one lane at selected points, and forcing motorists to slow down to maneuver between them. Such treatments are intended for use only on residential streets with low traffic volumes.
If there is no restriction (i.e., the number of lanes is maintained), chicanes can be created on streets with higher volumes, such as collectors or minor arterials.
Chicanes are horizontal traffic control measures used to reduce vehicle speeds on local streets. A secondary benefit of chicane installation is the ability to add more green (landscaping) to a street.
Costs for landscaped chicanes are approximately $10,000 (for a set of three chicanes) on an asphalt street and $15,000 to $30,000 on a concrete street. Costs should be far less for chicane-like parking configuration. Costs for chokers are estimated at $5,000 to $20,000. Drainage and utility relocation often represent the most significant cost consideration.
Authors and Acknowledgements