Sharrows and BMUFL Signs

Question

Susan asked: I am researching Sharrows to create a report on their efficacy for the Philadelphia streets department. The Department has asked us to create criteria and a publicity campaign. I noticed reference to your citing “state statutes and lane width requirements for sharing vs. controlling”.

I think this concept of when a bicycle shares vs. controls a lane would be helpful for us to discuss in our criteria. Can you give me more details about your state statutes and requirements?

Answer

The use of Sharrows and Bicycles May Use Full Lane signs is based on the statutes that define a “substandard-width lane” as too narrow for a motor vehicle and a bicycle to safely travel within the same lane.

By definition, it is necessary for an overtaking motorist to at least partially change lanes to pass a bicyclist, even if the cyclist is far right in the lane. This is discussed in detail in this post:

http://flbikelaw.org/2010/01/substandard-width-lanes-updated/

There is much more in the posts under the tags “substandard-width lanes”, “lane position”, ”narrow lanes” and “impeding traffic” in the tag cloud.

This post discusses Sharrows and BMUFL signs in one location and the public awareness campaign that was conducted:

http://flbikelaw.org/2012/03/bicycles-may-use-full-lanes-signs/

The use of these devices is new in Florida and there are only a few such installations. Separately, I will provide you with contacts that may offer more information about the experience regarding their application.

Posted in Ask Geo, Lane Width & Sharing Tagged with: , , ,
3 comments on “Sharrows and BMUFL Signs
  1. Dwight Kingsbury says:

    For placement of shared lane markings on state roads, see the details and table on sheet 1 of FDOT Design Index 17347 (http://www.dot.state.fl.us/rddesign/DS/13/IDx/17347.pdf ); the index sheet uses both terms, “shared lane marking symbols” (in the notes section at upper left) and “sharrows” (table at foot of the sheet). For use in a shared curbside travel lane less than 13 ft wide, the table indicates placement of the sharrow center 5 1/2 from face of curb except in a lane narrower than 11 ft, in which case the sharrow is centered in the lane, half way between lane line of the left and edge line on the right.

    FDOT’s criteria for use of the shared lane marking are set forth in section 8.4.5 of the Plans Preparation Manual (in 2013 edition, at http://www.dot.state.fl.us/rddesign/PPMManual/2013R/Volume1/Chap08.pdf ).

    Re use on their own roads, local jurisdictions are not subject to these two FDOT documents, but would need comply only with MUTCD 9C.07 (http://mutcd.fhwa.dot.gov/htm/2009r1r2/part9/part9c.htm#section9C07). Many cyclists have criticized the minimum lateral offsets described in the MUTCD, arguing that such placements do little more than reinforce far-right cyclist riding positions that contribute to inconsistent motorist passing behavior and to conflicts and collisions at driveways and side streets. The ITE Traffic Control Devices Handbook (2nd ed.) suggests (p. 590) the marking (if used) be centered in any travel lane of width not greater than 14 ft.

    The current (2011) edition of the FDOT manual known as the “Florida Greenbook” (http://www.dot.state.fl.us/rddesign/FloridaGreenbook/FGB.shtm), which establishes minimum standards for all public roads in the state not on the State Highway System, contains the statement (p. 9-6): “Wide outside lanes are through lanes which provide a minimum of fourteen feet in width. This width allows most motor vehicles to pass cyclists within the travel lane, which is not possible on more typical 10-foot to 12-foot wide lanes.”

  2. virgin@comcast.net says:

    Hi Susan, I hope you are not going to do what FDOT is doing. By having wide outside lanes in the PPM and adding sharrows to that lane, it gives FDOT the option of not installing bike lanes. Sunrise Blvd. is being resurfaced, it is an urban road in Fort Lauderdale within one mile of city center. It is in a heavily populated area, adjacent to Holiday Park. The city requested bike lanes and the request was denied.

    Because wide curb lanes with sharrows is allowable in the PPM there is no recourse, the curb lane will be 13′ wide, this is a 6 lane highway, there are 60,000 cars a day on this roadway. No one can convince me that this is in the cyclist best interest, the curb lane/sharrow lane will have the majority of truck and bus traffic.

    I am all for sharrows where bike lanes are not possible, but given the option of the two, I think bike lanes on heavily traveled streets are preferable. Width of pavement is 35 feet with 2 ft curb and gutter, speed limit is 35 and percent of truck traffic is less than 10%. Request was for 10′, 10′, 11′, lanes with 4′ bike lane. What will be installed is 11′, 11′ 13′ with sharrows.

  3. Geo says:

    Please note the quote in Dwight’s comment above about 14 foot wide curb lanes from both the Greenbook and the PPM:
    “Wide outside lanes are through lanes which provide a minimum of fourteen feet in width. This width allows most motor vehicles to pass cyclists within the travel lane, which is not possible on more typical 10-foot to 12-foot wide lanes.”

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