Risks of Sidewalk versus Road Bicycling

I promised a long time ago to post on the findings of studies on the risks of sidewalk versus on-road bicycling. From a 1994 paper by Wachtel and Lewiston studying bicycle-motor vehicle collisions in Palo Alto:

The average cyclist in this study incurs a risk on the sidewalk 1.8 times as great as on the roadway, and the result is statistically significant (p<0.01)…. Altogether the sidewalk risk is higher for 24 of the 27 categories [of cyclists], and for six of tehse the difference is statistically significant; for many groups the number of accidents expected is too small to attain significance.

The greatest risk found in this study is for bicyclists over 18 traveling against traffic on the sidewalk. Each of these characteristics is hazardous in itself; combined, they present 5.3 times the average risk.

Table 5 demonstrates that sidewalks or paths adjacent to a roadway are usually not, as non-cyclists expect, safer than the road, but much less safe. This conclusion is already well established in existing standards for bikeway design, although in our experience it is not widely known or observed.

[…]

Table 4 shows that wrong-way sidewalk travel is 4.5 times as dangerous as right-way sidewalk travel. Moreover, both Table 4 and Table 5 show that sidewalk bicycling promotes wrong-way travel: 315 of 971 sidewalk bicyclists (32 percent) rode against the direction of traffic, compared to only 108 of 2005 roadway bicyclists (5 percent).

Even right-way sidewalk bicyclists can cross driveways and enter intersections at high speed, and they may enter from an unexpected position and direction — for instance, on the right side of overtaking right-turning traffic. Sidewalk bicyclists are more likely than roadway bicyclists to be obscured at intersections by parked cars, buildings, fences, and shrubbery; their stopping distance is much greater than a pedestrian’s, and they have less maneuverability.

There is some nuance in the statistics. In reality, looking at all groups of bicyclists together, the rate of accidents (what the authors call ‘risk’) is higher for roadway bicyclists than for sidewalk bicyclists. But when cyclists are separated demographically by age, sex, and by whether they were cycling with or against traffic, for most such categories, it was riskier to cycle on the sidewalk than on the road. The reason for this apparent paradox is that higher risk is correlated with age, and age is correlated with cycling on the roadway. This meant that the large number of older cyclists on the roadways skewed the risk factor for roadway cycling higher than it actually was. If you compare cyclists in the same demographic category, though, roadway cycling was almost always less or equally dangerous.

(I would post the tables of data of all these studies if it wouldn’t run the risk of violating copyright laws. Nevertheless, those who want to see them may email me personally.)

Another study of cyclists in the Ottawa-Carleton region found a similar higher risk for sidewalk cycling:

Overall, travel on roads has the lowest injury and fall rates, followed by off-road paths/trails and then sidewalks. Collision rates are not different on the three types of facilities. The rate of injury might be considered most important by planners and cyclists from a safety perspective while the individual collision and fall rates might be considered important from the perspective of promoting bicycling if one wants to ensure positive travel experiences even when no injuries occur.

The relative rate of injury on the sidewalk versus the road is very high (4.0). Similarly, the relative
injury rate on sidewalk versus off-road paths/trails is quite high (2.5). While the relative rate of injury between paths/trails versus roads is lower ( 1.6) it is still significant and only seems small because of its magnitude compared to the other relative fall rates.consider the non-confounding and confounding variables.

Like the previous study, this one tried to eliminate the influence of confounding factors other than kind of path used. Instead of comparing risks category-by-category, though, they used other parts of their data to weight the risks they calculated accordingly.

Finally, a third study in Toronto finds that:

Overall, travel on roads has the lowest injury and fall rates, followed by off-road paths and then sidewalks. Collision rates are lower on sidewalks than on paths. But collision rates are higher on paths and sidewalks compared to roads. The relative rate of injuries and major injuries on the sidewalk versus both roads and paths is very high. While the relative rate of injury between paths versus roads is lower it is still significant for all injuries.

I should note that I did not cherry-pick these studies. I searched for studies that compared accident rates on the road versus accident rates on sidewalks, and did not find any that found a higher accident rate for road cyclists. You can try it yourself on Google Scholar.

Keep in mind, though, that even if road cycling has a lower risk of accident, a collision with a car is more likely to be fatal or result in serious injury than a fall on the sidewalk.

References:

Aultman-Hall, L. and F. L. Hall (1998, January). Ottawa-carleton commuter cyclist on- and off-road incident rates. Accident analysis and prevention 30 (1), 29-43.

Aultman-Hall, L. and G. M. Kaltenecker (1999, November). Toronto bicycle commuter safety rates. Accident Analysis & Prevention 31 (6), 675-686.

Wachtel, A. & Lewiston, D. Risk factors for bicycle-motor vehicle collisions at intersections. Journal of Safety Research 195.

About these ads

19 Responses to “Risks of Sidewalk versus Road Bicycling”


  1. 2 Ian Brett Cooper September 17, 2011 at 11:22 am

    The sidewalk is deceiving. It looks safe, but study after study has shown that it’s more dangerous to cycle on the sidewalk than on the road. The danger appears whenever the cyclist negotiates an intersection. Drivers simply do not look for people on the sidewalk (which is, incidentally, why walking is by far the most dangerous form of personal transportation).

    Sidewalks, bike paths and bike lanes are all death traps for cyclists, because they place the cyclist out of the motorist’s zone of awareness. As a cyclist concerned with keeping myself breathing, I avoid these places like the plague, and I advise others to do the same.

    Ride on the road – that’s what it’s there for.

  2. 3 Ian Brett Cooper November 12, 2011 at 12:12 pm

    You wrote: “Keep in mind, though, that even if road cycling has a lower risk of accident, a collision with a car is more likely to be fatal or result in serious injury than a fall on the sidewalk.”

    I think you’re missing the point here. The sidewalk statistics are not falls or collisions with static objects. They include collisions with cars in intersections. The statistics show that cyclists are more likely to be killed while riding on the sidewalk, because they have to cross roads at intersections. Wachtel’s study does not make the same mistake as Moritz’s 1997 study, where the site of the accident was the only consideration. Wachtel takes into account the cyclist’s position in the roadway and where he/she had been cycling before the collision. Jensen’s 2007 and Agerholm’s 2008 Danish studies confirm Wachtel’s findings on this.

    • 4 D December 6, 2011 at 12:00 am

      According to dictionary.com the definition of a road is “a long, narrow stretch with a smoothed or paved surface, made for traveling by MOTOR VEHICLE, carriage, etc between two or more points”

      The issue here is safety, its not common sense, its not sidewalk/road intersection versus road or sidewalk/road intersection vs sidewalk. You cannot blame drivers because a cyclists does not have the sense to stop when arriving at a road. The road is the only place where vehicles can drive, there is a reason for that, because of the speed they are capable of traveling and because of their mass and weight. Its a stressor and a nuissance to drivers for a cyclist to be on the road because everyone has to worry about not hitting the cyclist. Even when Peter the driver who cycles on the rode himself when he is not a motorist on the road probably thinks of this as a nuissance as well. There is no argument here. Tell cyclist to stay on the sidewalk and use caution or ride in a park or someplace away from traffic, period.

      I can’t tell you how many times I have to drive way below the speed limit because some bike rider chooses to disrupt traffic on a busy street instead of using a neighborhood or park to ride, these are not commuters going to and from work, these are recreational cyclist. We shouldn’t have to watch how we drive because cyclists want to use an alternate path of travel. Its dangerous for the cyclist and it causes motorist to motorist hazards and stressful situations as well. Unless its NYC where traffic is extremely slow and decision time is much much slower, than stay off the roads and stop disrupting traffic, I’m not saying this out of anger, I’m saying this because its common sense and for the safety of all drivers, their passengers, and the cyclist.

      I like to call myself an extremeist-recreationalist, I like to Mountain Bike in rough terrain, Snowboard, ride ATV’s, go 4x4ing, jet sking, mountain climbing, canyoneering, and hiking. There is not much that I’m afraid, definitely not riding a bicycle in traffic, I do not ride on roads because its a courtesy to motorist and because its a safety issue to myself and them. I can ride on a sidewalk without running into walkers or getting hit by a car at an intersection.

  3. 5 Ian Brett Cooper December 6, 2011 at 12:28 am

    Roads were created at the behest of cyclists in the 1890s. Because of this, a bicycle is considered a vehicle in all 50 states and is REQUIRED to operate on the road in most places. Traffic law exists precisely to prevent those who drive large vehicles from ruling the road. Might makes right has never been a part of any traffic code, because a code with such a basis would be stupid.

    Traffic law is based on the concept of ‘right of way’. If a vehicle in front of you is on the road, he has the right of way and you have to follow or pass safely. The idea that you should have the right of way when a vehicle in front of you is traveling too slowly for your convenience has never been a part of traffic law because it would get people killed.

    Your argument is based on ignorance of traffic law. Go study your driver’s handbook. How people like you even get licensed, when you have not the slightest clue about traffic law or road safety, is a mystery to me.

  4. 6 John Schubert, Limeport.org December 7, 2011 at 2:08 pm

    Roads are for people. Some people are in cars. Some aren’t. People have a right to travel, and that right is not circumscribed by anyone else’s notion of the worthiness of their travel.
    There is no entitlement to drive as fast as possible.
    Mr. D’s odd feeling that driving becomes so difficult in the presence of law-abiding bicyclists tells me that he’ll understand Ian’s excellent scholarship better if he begins by getting to know the concept that roads are for people.

  5. 7 nocklebeast December 7, 2011 at 6:11 pm

    “Its a stressor and a nuissance to drivers for a cyclist to be on the road because everyone has to worry about not hitting the cyclist.”

    This is true for all drivers of vehicles. All drivers of vehicles must take care not to hit other vehicles, whether they are bicycles, buses, trucks, trains, or cars. This is part of what it means to be a driver of a vehicle.

    If you’re really that stressed out about it, perhaps you shouldn’t be driving.

  6. 8 Randall Flagg September 15, 2012 at 2:06 am

    Got news for you; I *did* Google exactly what you did, and you know what I got? http://www.ncbi.nlm.nih.gov/pubmed/10487343?dopt=Abstract ….”The rate of collision on off-road paths and sidewalks was lower than for roads”…

    • 9 ianbrettcooper September 15, 2012 at 9:14 am

      Yes, the rate of ‘collision’ was lower than for roads. But of course that’s going to be true – you don’t tend to collide with vehicles on a sidepath. However, the study’s abstract goes on to say, “The relative rates for falls and injuries suggest these events are least common on-road followed by off-road paths, and finally most common on sidewalks. The rate of major injuries, an injury that required medical attention, was greatest on sidewalks and the difference between paths and sidewalks was negligible.”

      In fact, the vast majority of peer-reviewed studies support the fact that sidewalks, sidepaths and even bike lanes are more dangerous than riding in the road. Check out the following:

      http://ianbrettcooper.blogspot.com/2012/08/bicycle-infrastructure-studies.html

      There you’ll find a list of all the cycling safety studies that are available on the web, including the most interesting quotes, and/or an assessment of any bias in the study, and a link to the study itself, so that anyone can check out the full text.

      Almost 90% of studies conclude that riding a bike on specialized bicycle infrastructure is less safe than simply riding in the road with traffic.

      • 10 Kevin August 2, 2013 at 5:13 pm

        I feel as if I need to mention about the geographic differences of what you are trying to say. I will agree that cycling in the road is safer because cyclists are most visible there. The slower the road though, the safer. However, while cycling infrastructure can look unsafe to us, it gives the feeling of security while biking and it is less stressful to cycle at a slower speed without having that feeling of impeding traffic. Cycling infrastructure though has to be done in a way that will make cyclists visible at intersections. It generates more people cycling, and that will have a positive effect as it’s raising awareness of cyclists, so motorists can expect them more. Just look at Amsterdam and Copenhagen. They have very good infrastructure for cycling and people ride there without even thinking about it. Another example is Montréal where a lot of cycle lanes have been placed along with a bike-sharing program. Now more and more people cycle there.

  7. 11 ποσειδώνιο April 6, 2013 at 5:32 am

    Hi to all, how is everything, I think every
    one is getting more from this site, and your views are nice
    designed for new viewers.

  8. 12 coupons April 13, 2013 at 6:45 am

    I do accept as true with all the concepts you’ve introduced to your post. They’re very convincing and can certainly work.

    Still, the posts are very brief for beginners. May
    you please prolong them a little from subsequent time?
    Thank you for the post.

  9. 13 blog July 2, 2013 at 9:27 pm

    Should all of the necessary features to watch for before choosing a service.
    .. This is as a result of water drainage and sun time that
    the Buckeyes were wondering, toyo is not careful. Benidorm plus Alicante is the
    largest cities in the wine has been drank, it is likely the bottle around by the south and
    east by the company that made them. Wood is still the
    most like to remain inside the north, the Tagus River in the occasional bottle of wine?

  10. 14 youtube July 17, 2013 at 8:58 pm

    Spot on with this write-up, I seriously feel this site needs a
    lot more attention. I’ll probably be returning to read through more, thanks for the advice!

  11. 15 personal injury attorney macon September 26, 2013 at 3:16 am

    My developer is trying to persuade me to move to .net from PHP.

    I have always disliked the idea because of the costs.
    But he’s tryiong none the less. I’ve been using WordPress on a variety of websites for about a year
    and am concerned about switching to another platform.
    I have heard great things about blogengine.net. Is there a way I can import all my wordpress posts into it?
    Any kind of help would be greatly appreciated!

  12. 16 haylazr.blogspot.com October 3, 2013 at 10:28 am

    Pretty portion of content. I just stumbled upon your site and
    in accession capital to assert that I get in fact loved account your weblog posts.
    Anyway I will be subscribing for your feeds or even I fulfillment you access persistently quickly.


  1. 1 Sidewalks or Street? « In The Spin Trackback on June 12, 2008 at 1:08 pm
  2. 2 One More Step to Marginalisation « One Less Car Trackback on June 25, 2008 at 5:44 pm
  3. 3 Spartan Daily ignores safety risks « My unions, CSUEU & CFA! Trackback on November 24, 2009 at 8:01 pm

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s





Follow

Get every new post delivered to your Inbox.

%d bloggers like this: