28
Oct 2008
by mark

When sidewalks and sidepaths are suitable for bicycling

sidepath on Hawthorne bridge in Portland, Oregon
There’s plenty of articles and statistics out there damning the practice of riding a bike on a sidewalk.

That’s why I so surprised to come across what’s seen in this photo from Portland, Oregon, the bike capital of the United States.  On the Hawthorne bridge, bike traffic is directed on to the sidewalk.

As luck would have it, a Traffic Safety Specialist  in Portland noticed I was posted bike photos of Portland on Flickr, and invited me out for a beer while I was visiting.

Greg Raisman was prepared to be questioned about that. He was aware of the same bikes-on-sidewalk-are-evil rhetoric. He explained this was technically a sidepath, and the important difference here is how the traffic is managed in the facility.

A sidewalk typically has many conflict points with motorized traffic– driveways and intersections. Those are the places where accidents to tend to happen on sidewalks and are the source of the danger from riding bikes on them.

On Portland’s Hawthorne bridge sidepath there are zero conflict points between bikes and cars. Cyclists roll up their own ramp to enter the facility from a bike lane. There are no roads or driveways to cross on the bridge while traveling westbound, and cyclists have their own exit ramp at the other end (rather than being dumped at an intersection). Meanwhile, the curb physically separates the bike traffic from the cars, providing extra  safety and security compared to a painted stripe on the road.

I think the League of Illinois Bicyclists may have the right idea with their Sidepath Trail Calculator.  Rather than being simply for or against bikes on sidepaths, they calculate a rating based a number of factors, such has how many driveway and road crossings there are along the path.

I still believe that there are many cases where riding a bike on sidewalk or sidepath could be more expensive for a city to support and more dangerous for bicyclists.  Bridges generally don’t have intersections in the middle of them and strike me as a place where a sidepath could be a safe and effective facility for bicyclists.

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  • http://limeport.org John Schubert

    You state, quite correctly, that “A sidewalk typically has many conflict points with motorized traffic– driveways and intersections. Those are the places where accidents to tend to happen on sidewalks and are the source of the danger from riding bikes on them.”
    In addition, bike/ped collisions are a major concern (as shown by accident statistics), largely because pedestrians behave more randomly and unpredictably. Asking pedestrians to march in formation is unrealistic.
    All of this leads to a major concern:
    Many bicyclists don’t understand these concerns. That’s why so many of them wind up in the sidewalk and sidepath statistic accidents.
    If you put bicyclists on a sidewalk or sidepath on one street, that “educates” the bicyclist to use the sidewalk or sidepath on the next street. The fact that the next facility may have driveway intersections, blind curves, narrow pavement, etc., is too subtle for the cyclist to appreciate the differences.
    This is one reason why I’m wary of “exception to the rule” facilities. The public’s knowledge level is poor, and this just makes it poorer. This is a way to indirectly encourage hazardous behavior in other places.
    My 27 years of work in accident reconstruction give me a high level of confidence in my statement about the poor knowledge level. When people who have been in accidents are interviewed, many of them are oblivious to the kinds of factors we look at in these discussions.
    Note that much of your commentary concerned a specific bridge, and I am not attempting to evaluate the specifics of that bridge, but rather, the other issues that you touched on.
    John Schubert
    Coopersburg, Pennsylvania
    schubley@aol.com
    limeport.org

  • http://mark.stosberg.com/ Mark Stosberg

    John,
    I thought I recognized your name as the Technical Editor at Adventure Cyclist magazine. Thank you for the informed comment.

  • Mark Stosberg

    Noted bicycling advocate John S. Allen has posted a response on his blog

  • Mark Stosberg

    John, you mention “bike/ped collisions are a major concern (as shown by accident statistics)”. I’m interested to learn more about this…could you point me to some of the best primary sources of bike/ped accident statistics?
    Looking particularly at Portland, I found this 4 Meg PDF of Portland’s recent bike stats. Looking at page 12, There’s a graph that shows ridership going up steeply, while the relative number of crashes decreases steeply, approaching zero.
    Portland appears to have the kind of success that I associate with European bike systems– high participation and low injuries.

  • http://john-s-allen.com John Allen

    The crash rate Portland reports for the city as a whole does not address the question whether the Hawthorne Bridge sidewalk is hazardous. A recent crash there narrowly avoided being fatal. Factors in that crash were crowding with bicyclists and pedestrians, lack of caution by some, and the dropoff over the curb to the grid deck carrying motor traffic. Bicyclists need to ride slowly on the bridge, and even so can get into trouble.
    I have some additional online comments about the Hawthorne Bridge and your posting.
    Looking at the larger picture, the Portland statistics are based on reported crashes, which are mostly car-bike crashes. It is reasonable to expect the rate of car-bike crashes to decrease with increasing numbers of bicyclists, as motorists become more alert and because, if there are more bicyclists, the average bicyclist has been riding longer. But note that the scale on the graph you refer to is different on each side — the crash rate goes down by a factor of about 5, not to nearly zero. Yes, it’s safer for an individual bicyclist. On the other hand, the crash numbers remain about the same, and so the burden of bicycle crashes on society at large also does.
    I would like to see data from hospital emergency rooms, which would take in crashes that were not reported to police. I suspect that the rate for such crashes has not decreased as much.