Monday, June 21, 2010

sharrows as wayfinders

the device over there on the right, with the silhouette of the bike and the two chevrons, is a "shared lane marking," or more colloquially, a "sharrow."

the 2009 manual on uniform traffic control devices includes the sharrow at section 9C.07 as an optional treatment on roads on which the outer travel lane is too narrow to share. the intended purpose of the device is to indicate "lateral lane positioning," that is,
(a) to tell cyclists they should move to the left, away from the curb or out of the door zone, and
(b) to tell motorists they should expect to see cyclists claiming the entire lane.
the device may be used in conjunction with signage indicating "bicycles may use full lane," though this is not required.

over the past several weeks, PBoT has been putting these down on some of the newly designated bike boulevards -- klickitat, holman, going, etc. but they are not being used to indicate lateral lane positioning. they are being used as wayfinders.

evidently, PBoT made this choice because there was stimulus money available, but they needed to use MUTCD compliant signage and pavement treatments to get the grant. they did snag close a million dollars for this project, but it seems to me the money would have been better spent putting sharrows where they are actually needed, for example on northeast 28th, or on southeast hawthorne, or on the couch/burnside couplet. evidently putting sharrows on those roads is not a priority for PBoT.

as wayfinders, the sharrows are quite visible. but something else on a similar scale would have served just as well, though the money would have had to come from some other source, maybe bioswales.

my objection is not only that we need sharrows elsewhere, but that they are inappropriate here. lane positioning is not really an issue on a bike boulevard, where there is hardly any motor traffic, relatively few cars parked on the street, and average speeds are in the teens and low twenties.

and to make matters worse, on the narrower streets, like klickitat and holman, these sharrows have been placed not just to the left of the door zone, as contemplated in the MUTCD, but right on the center line (sometimes, weirdly, slightly to the left of center). this completely negates the intended purpose of the sharrow, diluting its usefulness in situations where it is actually needed.


  1. +1, like, what he said, amen.

  2. I agree with you that sharrows would be most highly beneficial on streets like NE 28th and/or Alberta, Belmont and Hawthorne, etc. The sharrows do seem a little much on Bike Boulevards, but I see any bicycle infrastructure as a net positive gain for the community.

  3. Some good points, Russ. Although I would have to argue that lane positioning still is an issue on some BBs in town. On routes like Tillamook between MLK and Williams and Ankeny between 7th and the river people driving cars (PDCs)are still unaware of the street's designation and I think the more signage/labeling the better.

    I've also missed some of the smaller way-finders while riding myself because they're easy to pass up, so I'm not against a larger-scale marker... maybe a compromise would be good, though.

  4. i agree the large-scale wayfinders are useful, and they give the road a different "feel," which i think probably conveys a useful message to motorists. but the same result could have been accomplished (albeit not on obama's dime) with some other emblem. the sharrow has a specific meaning, and this use of the sharrow dilutes that meaning.

  5. I think that the use of the sharrows, at least on the streets I've seen them on, are perfectly placed and much appreciated. I bike on SE Salmon and Ankeny most frequently. Both BB's are highly known as such and yet there are still many motorists that zip up and down them without much thought for cyclists. When these drivers do pay attention to us, its annoyance as they can't wait to get around us. The level of visibility the sharrows provides on these streets very clearly tells motorists that cyclists belong there and that they need to relax. Everyone I've spoken with about the use of the sharrows has had positive response- several saying they make them feel much safer and confident about taking the lane. As someone who has been both hit by a turning car and doored, I can say that its a great relief to be able to point at the road sign when angry motorists honk at me for taking the lane to avoid the door areas.
    As an aside, Belmont has a designated bike lane already up till around 24th. Beyond that, I think Belmont and Hawthorne should both be left to autos so they can zip along and leave our routes (such as Salmon St.) alone.

  6. i guess there is stuff here on which we will have to agree to disagree. i am saying i think larger scale wayfinders are a good idea, and i am acknowledging that they may have something of a traffic calming effect. my gripe is that the specific device they are using to accomplish this -- the sharrow -- is intended for something completely other, and that to use it in this way will dilute its effectiveness for its intended purpose. for example belmont and hawthorne.