Anatomy of a Bicycle Friendly Street: Chicanes

(Ed Note: Most of the information on Bicycle Friendly Street treatments in this post  comes  from the new Bike Plan’s Technical Design Handbook.  Though we are happy to present it in bite-sized pieces, we highly recommend you download it yourself and have a good read.  You can download the Technical Design Handbook here.  For a refresher on Bicycle Friendly Streets generally–read our introductory post here.)

An example of a chicane from Austin, TX

It’s time for yet another installment in our ongoing series that details the specific treatments that go into making a Bicycle Friendly Street (BFS). Today, we will examine chicanes – a traffic calming device. Traffic calming devices are considered “Level Four” BFS applications based on level of physical intensity. It is important to note that BFS applications are site-specific, and that not all streets require the highest application treatments. The Bike Plan Technical Design Handbook (TDH) recommends gathering community input along with the necessary engineering and design work to determine the level of application necessary for each individual street. In case you were wondering, there are five different application levels – varying from signage to traffic diversion.

Chicanes

Chicanes are  alternating curb extensions that create an S shaped curve in the street. They are categorized as horizontal deflectors – as opposed to vertical deflectors like speed bumps. Chicanes are best utilized along narrow streets so that cars will be more inclined to slow down. Their primary purpose is to slow vehicular traffic, but they may also be used to beautify neighborhoods through improved landscaping.  Chicanes can also enhance the pedestrian experience through expanded curbs areas.

Advantages:

  • Chicanes discourage high vehicle speeds by creating an S shaped bend in the road
  • They have minimal impact on emergency response vehicles compared to speed bumps, speed humps and other vertical deflection measures.

Disadvantages:

  • Some on-street vehicular parking may need to be removed
  • The narrowing of the road may force bicyclists to move into vehicular traffic flow

Here’s a nice visual provided by Streetfilms that details how chicanes work!

[vimeo http://www.vimeo.com/12796823 w=400&h=300]

Chicane – Animated Traffic Calming from Streetfilms on Vimeo.

Things to Consider

Chicane application costs can vary greatly depending upon the treatment’s intensity. Configuring on-street parking to create a chicane effect is the most inexpensive design solution, but it lacks neighborhood beautification features (landscaping, curb extensions, etc). It is important to note that upkeep is usually the responsibility of a neighborhood group – similar agreements are needed for round-a-bout’s with landscaping.

Chicanes with curb extensions and landscaping can be quite costly, especially if there are drainage issues. Drainage issues are very important as  any treatment that impedes the flow of water may cause unnecessary flooding. Drainage issues must be mitigated during the design phase of any BFS facility.

We close with some lovely images of chicanes – enjoy!

Painted chicane treatment courtesy: Federal Highway Administration (FHWA)

Landscaping improvements compliments of a chicane – via PBIC

A great neighborhood chincane example from Toronto via PBIC

0 replies
  1. Richard Masoner
    Richard Masoner says:

    The “bike must move into traffic” disadvantage can sometimes be mitigated by creating a straight across “bike channel” across the chicane. The problem with the bike channel is they can collect debris, though design can work around that issue as well.

    Reply
  2. PlebisPower
    PlebisPower says:

    Thanks for reminding us of the traffic-calming tools that DO exist and ARE deployed elsewhere but, to date, just not here. The best example of chicanes – Austin – reminds us that they not only serve a functional purpose (calming) but when handled properly give our streets an organic quality too often lacking, esp in the Los Angeles area. Nature enthusiasts are fond of pointing out how nature literally permeates our urban environment, such as when plants push up through the concrete. Chicanes like those in Austin give us an opportunity to reassert nature in the most banal of urban environments: streets predominantly reserved for people and not cars.

    If there is not a case study database of innovations like the chicane there ought to be one. Then advocates can have a range of examples (as shown above) to which we can refer for context-specific examples.

    Reply
  3. John Vance
    John Vance says:

    They installed those in my old neighborhood in Salford UK. Drivers would take them at the highest speeds they could. Late at night you could hear 1.3 litre engines revving to their limits and tiny tires squealing as the local yobbos treated it like Nurburgring.

    In the same neighborhood, they tried planting saplings to to soften the urban landscape and give the streets an even narrower appearance. The kids loved to bend and snap those.

    Reply

Trackbacks & Pingbacks

  1. […] small scale roundabouts, speed tables, chicanes, and textured road surfaces (this brick street in Portland leaves smooth strip for bikes) that […]

  2. […] have a series of traffic calming devices, Sharrows, road signs, directional signs, traffic circles, chicanes, loop detectors, diverters, […]

  3. […] for bikes, pedestrians and other neighborhood users. Traffic calming measures (roundabouts, chicanes, diverters, etc) may help ensure that cars do not speed on 4th Street. By restricting through […]

  4. […] a Bike Boulevard- you can read our introductory post here. You can also find previous posts on chicanes, round-a-bouts, loop detectors and other BFS treatments […]

  5. […] offering up to $2,500 for neighborhood improvement projects within his district. LADOT Bike Blog looks at chicanes, my favorite traffic calming method to ride. The LookOut News profiles LACBC affiliate Santa Monica […]

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