Anatomy of a Bicycle Friendly Street: Diverters

There has been a lot of talk lately, both on this blog and elsewhere, about Bicycle Friendly Streets (more commonly known as Bicycle Boulevards).  The LACBC has long been campaigning to turn 4th Street into a Bicycle Boulevard.  Rich Risemberg reports that Council Member Tom LaBonge is also committed to a Bicycle Boulevard on 4th Street.  CicLAvia’s route went along 4th Street, giving an idea of what a Bicycle Boulevard could be.   Waring Avenue has also been identified as a site for a Bicycle Boulevard, both by Council Member Tom LaBonge and by Hollywood Examiner writer Taylor Nichols.  In terms of a street in LA that already most closely resembles a Bicycle Friendly Street, Westholme Avenue might have the strongest case.

Sharrows AND traffic circles? Be still my beating heart!

But sometimes lost in the shuffle is what, exactly, makes up a Bicycle Friendly Street or Bicycle Boulevard?  How are they different from other streets?  What is installed and why does it make bicycling safer?  How much does it cost and how does it get installed?  Come along with LADOT Bike Blog as we examine the:

Anatomy of a Bicycle Friendly Street

Diverters

Bikes go through. Cars? Not so much

(Ed Note: Most information on Bicycle Friendly Street treatments come from the Technical Design Handbook in the draft 2010 LA Bike Plan.  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 what a Bicycle Friendly Street is -also called a Bike Boulevard- you can read our introductory post here.)

If a Bicycle Friendly Street is a baseball team, Traffic Diverters would be the cleanup hitters.  A Traffic Diverter’s purpose is to direct vehicle traffic away from a Bicycle Friendly Street while allowing through travel for bicycles.  Traffic Diverters have also been shown to raise property values and make streets a more pleasant place to live.  The City of Berkeley uses Traffic Diverters not only to facilitate Bike Boulevards, but also to discourage through traffic on their residential streets.  When drivers treat collector streets as a bypass to nearby busy arterial streets, it can create dangerous road conditions and an unpleasant living experience.  Traffic Diverters put car traffic back where it belongs while providing a safe, enjoyable neighborhood environment for bicyclists, pedestrians, children, and pets.

Traffic Diverters are the top-of-the-line treatment for a Bicycle Friendly Street, listed in the draft Bike Plan as the level 5 treatment out of 5 levels.

Diagonal Diverters

This diverter is placed diagonally across the intersection to impede through car traffic in all directions

Diagonal diverters are meant for an intersection of a local street with another local street.  Since local streets are not designed for through traffic, a diverter will encourage drivers to use these streets for their appropriate purpose.  Typically, a diagonal diverter can have a wide paved center which blocks through traffic with a flexible or removable bollard.  This design feature can be placed to allow emergency vehicles to pass through when necessary.

A diverter at Catalina & 4th, imagined by CicLAvia

Diagonal diverters typically cost between $4,000-$10,000, and newer designs for diagonal diverters may call for drought-resistant landscaping that can, with the support of the community, tie them into the feel and fabric of the surrounding neighborhood.

Raised Median/Crossing Islands

Raised medians and crossing islands come in many forms

While a diagonal diverter is only appropriate for smaller residential streets, installing raised medians or crossing islands can improve a Bicycle Friendly Street where it meets with a larger arterial street.

As shown in the photo above, a raised median/crossing island allows through traffic for bicycles along a Bicycle Friendly Street while directing drivers onto an arterial street more appropriate for car traffic.  While a diagonal diverter redirects traffic in all directions, a raised median only redirects traffic from the Bicycle Friendly Street.

Raised medians/crossing islands also make the crossing of larger arterial streets much easier and safer for a bicyclist.  By providing a protected space between directions of traffic, a bicyclist can cross a street one direction of traffic at a time.

 

This crossing island, with its zig-zag design, forces pedestrians to look at oncoming traffic before continuing across the street

Check back next week for more Anatomy of a Bicycle Friendly Street.

0 replies
  1. PlebisPower
    PlebisPower says:

    Love the rendering. This is just what folks need to help them imagine a future that makes possible fluid cycling and safe pedestrian access though what are today congested and perilous intersections. The perspective, color, and text explanations in particular really give life to what are often illustrations only an engineer could embrace. We can’t expect everyday folks to embrace nontraditional street treatments in a region that has known few of them. By putting out there accessible illustrations like this one, the public is better equipped to envision street improvements that are a win-win all around.

    Reply
  2. Joe Linton
    Joe Linton says:

    The image you’ve credited to CicLAvia did indeed run at our blog – and I am glad to see it promoted by the LADOT – but it’s not actually our work. It’s the work of Aaron Kuehn!

    Isn’t it beautiful!?! If you want to see it become a reality, get involved in the LACBC campaign for a true bike boulevard on 4th.

    Reply

Trackbacks & Pingbacks

  1. […] 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 movements for […]

  2. […] of what surely is your favorite bicycle infrastructure series.  Last time out we covered Traffic Diverters – the Cadillac of BFS treatments.  This week we’ll look at a much smaller, but no less […]

  3. […] levels of treatments that can be applied to the streetscape.  The most robust of these treatments (like diverters, covered earlier this week on LADOT Bike Blog) are analogous to the bicycle boulevards of cities […]

  4. […] This post was mentioned on Twitter by Rick Risemberg, SBBikeCoalition. SBBikeCoalition said: RT @bicyclefixation: "Anatomy of a bicycle-friendly street" from LADOT Bike Blog: http://tinyurl.com/2dcv4dq […]

  5. […] to buses and subways. Claremont Cyclist offers a meditation on the biking derriere. LADOT Bike Blog looks at the traffic diverters that make a Bicycle Friendly Street bike friendly. An OC bike advocate says every issue in bike […]

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