Cycle Tracks are NINE TIMES safer than roads?

There was a glowing article in theatlanticcities.com with the tantalyzying headline Dedicated Bike Lanes Can Cut Cycling Injuries in Half,  referring to this study, published in a peer-reviewed, albeit public health and not a transportation, journal:

Route Infrastructure and the Risk of Injuries to Bicyclists: A Case-Crossover Study Kay Teschke, PhD et al.  Am J Public Health. 2012;102:2336–2343. doi:10.2105/AJPH.2012.300762  [pdf]

The design of the study is intriguing: it’s based on randomly choosing a “control site” along the participant’s (i.e. the crash victim) route.

Cycle Tracks are NINE TIMES safer?

Undoubtedly, the incredibly safety differential of “cycle tracks” will be the main take-away. The study found them to be NINE TIMES safer compared to their reference street (essentially a “worst case”: a mulitlaned arterial with on-street parking and no bicycle facilities whatsoever). The actual result is OR 0.11 (0.02, 0.54) — that is to say Odds Ratio of 11 percent, with a 95% confidence interval between 2 and 54%, compared to the reference road.

Ok, so I don’t understand a lot about statistics, but the wide range between the lower and upper confidence interval (27X) is a clue. In short there is not very much/many cycle tracks in the study, mentioned only as “despite their (cycle track’s) low prevalence in Toronto and Vancouver”. There were two reported collisions, and 10 control sites on cycle tracks (out of N=648). In the critique of the study by John Forester he found during the study period there was apparently only one cycle track, the Burrard Street bridge, in both cities — my that is a “low prevalence” — here is his take-away:

In the much more impressive cycle-track issue, the authors proclaimed enormous crash reduction without informing the readers of the two relevant facts. First, that their data came from only one installation. Second, that that installation was not along a typical city street but in the only situation in which a plain cycle track could possibly be safe, a place without crossing or turning movements by motorists, cyclists, or pedestrians…

And even regarding the Burrard Street Bridge cycle-track, the timeline seems to conflict/overlap somewhat with the study dates. According to a surprisingly detailed account on wiki a test of what sounds to be the cycle-track was “to begin in June 2009. The proposed trial began on July 13. It saw the southbound motor-vehicle curb lane and the northbound-side sidewalk allocated to bicycles, with the southbound-side sidewalk allocated to pedestrians. The reassigned lane was separated from motor vehicles by a physical barrier” The timeline of the study was for bicyclist injuries presenting to the ERs “between May 18, 2008 and November 30, 2009″.

But wait? According to this (from mid-2011, i think, the date is unclear), Tesche said there are other cycle tracks:  “However, we were able to examine separated bike lanes elsewhere in the city, including Burrard Bridge, Carrall Street, and other locations that met our definition: that is, a paved path alongside city streets that’s separated from traffic by a physical barrier,” Teschke told councillors.

Some Other Things i Noticed

The highest median observed motor vehicle speed along major roads was 44kph (27mph)! This is comically low compared to what I am used to here in Phoenix. Intersting trivia answer: 27.79mph —  the fastest time on record for a person running.

One-third of the incidents involved collisions with MVs. The balance were various types of falls or collisions with objects. The one-third number is pretty close to the 26% reported by another ER-based survey of bicyclist injuries (  Injuries to Pedestrians and Bicyclists: An Analysis Based on Hospital Emergency Department Data.  linked here ); though this isn’t directly comparable, e.g. in the former case, mountain biking was not eligible for the the study, whereas in the latter it was any sort of injury incurred on a bike.

There was a bunch of interesting data collected in the survey (which the author’s are nice enough to give a link to) that are not in the final study. I’m not sure why. I would have been interested to see various spins on lightness/darkness vs. cyclist’s light usage.

The Injury Prevention Article

and here’s another similar article, or perhaps pretty much the same(?):

Comparing the effects of infrastructure on bicycling injury at intersections and non-intersections using a case–crossover design Inj Prev doi:10.1136/ip.2010.028696 M Anne Harris, Conor C O Reynolds, Meghan Winters, Peter A Cripton, Hui Shen, Mary L Chipman, Michael D Cusimano. Shelina Babul, Jeffrey R Brubacher, Steven M Friedman, Garth Hunte, Melody Monro, Lee Vernich, Kay Teschke

 

NYC Protected Bike Lanes on 8th and 9th Avenue in Manhatten

According to a report (it’s really a brochure) by NYC DOT cited by  americabikes.org; these are the “First protected bicycle lane in the US: 8th and 9th Avenues (Manhattan)”…”35% decrease in injuries to all street users (8th Ave) 58% decrease in injuries to all street users (9th Ave) Up to 49% increase in retail sales (Locally-based businesses on 9th Ave from 23rd to 31st Sts., compared to 3% borough-wide)”. I don’t know if or what the data are to back up these claims. I also don’t know much about how these are structured, what was done with signals, how long these are,  or how long they have been in place… here is a google street view at 9th/23rd. (these segments show up in Lusk’s May 2013 AJPH article, discussed below)

Study of Montreal Cycle Tracks

Likewise, Harvard researcher Anne Lusk, et. al (includes Peter Furth, Walter Willett among others) has claims of safety increases  Risk of injury for bicycling on cycle tracks versus in the street, brief report Injury Prevention. Streetsblog.org is expectedly uncritical, but a through rebuttal by mathemetician M Kary can be found hosted on John Allen’s site(older, 2012), and more recently (Jan2014) including links to Kary’s two original unedited letters, as well as the published commentary in Inj Prev. , which includes a rebuttal from the authors. There is some other rebuttal from Ian Cooper, in a comment below.

Methodology aside, though the study claims an increase in safety, it found only a modest increase: “RR [relative risk] of injury on cycle tracks was 0.72 (95% CI 0.60 to 0.85) compared with bicycling in reference streets”. I.e. a 28% reduction in crashes.

They had an interesting reference to Wachtel and Lewiston 1994, a much-cited sidewalk study.

More Lusk, July 2013 Article in AJPH

Oh, it’s like it never ends:

Bicycle Guidelines and Crash Rates on Cycle Tracks in the United States
Anne C. Lusk, PhD, Patrick Morency, MD, PhD, Luis F. Miranda-Moreno, PhD, Walter C. Willett, MD,  DrPH, and Jack T. Dennerlein, PhD Published online ahead of print May 16, 2013; it was in the July printed edition of American Journal of Public Health. “For the 19 US cycle tracks we examined, the overall crash rate was 2.3 … per 1 million bicycle kilometers… Our results show that the risk of bicycle–vehicle crashes is lower on US cycle tracks than published crashes rates on roadways”. What are published rates? Later they say “published crash rates per million bicycle kilometers range
from 3.75 to 54 in the United States”. The first number is footnoted to Pucher/Irresistible (which is discussed and linked here), and the second to, if you can believe it, a study of Boston bicycle messengers (Dennerlein, 2002. I haven’t bothered to look that one up). In Pucher, it’s in Fig 10  where they quote US injuries at 37.5 per 10 million km for the period 2004-2005, sourced to US Department of Transportation (2007), which is/are Traffic Safety Fact Sheets according to the footnotes. Pucher does, um, mention that injury rates comparisons across countries are particularly suspect; Figure 10 would lead on to believe the UK and US have similar fatality rates, whereas US injury rates are quoted as SEVEN TIMES higher. (Pucher’s claim/point is that NL and DK are very safe, while US and UK are very dangerous). In any event TSF does not list injury rates per unit of travel, only number of injuries, e.g. TSF 2005 quotes 45,000 injuries (these are presumably some sort of statistical estimate?).  To get the rate estimates, he uses one of the surveys (household trans survey?).

Paul Schimek gathered data on the 19 cycletracks listed in table 3; he added another column “intersections per km” and sorted them into two groups, 1) Urban Side Paths and 2) Side Paths with Minimal Crossflow. And as would be predicted by traffic engineering principles, the former had very high (7.02) versus the latter which had very low (0.57) crashes per 1 Million bicycle kilometers. The published letter-the-editor of AJPH is available in full on pubmed (or draft version on google docs) which is well worth reading. He, by the way, provides an estimate for whole US bike crashes at 3.5 per 1M bike km’s; which fits rather nicely between the high/low cycletrack numbers. The bottom line is that the AASHTO guidelines (which prohibit the on-street barriers; but permit bicycle paths adjacent to the roadway where there is “minimal cross flow by motor vehicles”) , contrary to Lusk’s assertions, are well-founded. This blog post at  bicycledriving.org also discusses the same AJPH article, with links to both Schimek’s published letter, and Lusk’s published response. This is wrapped up in an article the Paul wrote A Review of the Evidence on Cycle Track Safety, Paul was kind enough to send me draft copy dated October 10, 2014.

Oh, and here is John Forester’s review of Lusk’s May AJPH article. In summary, Forester says “This review does not evaluate Lusk’s method of calculating car-bike collision rates. However, the cycle tracks with high collision rates are all in high-traffic areas with high volumes of crossing and turning traffic, while the cycle tracks with low collision rates are all in areas with low volumes of turning and crossing traffic. That is what should be expected, but it says nothing about any reduction in collisions that might have been caused by the introduction of cycle tracks. The data of this study provide no evidence that cycle tracks reduce car bike collisions”.

What about Davis, CA?

Late-1960s parking-protected cycletrack, Davis, California
Sycamore Lane Experiment:1967 parking-protected cycletrack, Davis, California (Photo: Bob Sommer)

The article/thesis paper Fifty Years of Bicycle Policy in Davis, CA 2007
Theodore J. Buehler has a deep history. Davis, home of course to UC Davis, installed and compared designs including what we would now call a cycle track, (emphasis added):

Lane location relative to motorized traffic
The early experiments included three different types of bike facilities (see examples at the top of this section):

  1. bike lanes between car lanes and the parking lane (Third St.),
  2.  bike lanes between the parking lane and the curb (Sycamore Lane), [what we now call a cycle track, or protected bike lane] and
  3. bike paths adjacent to the street, between the curb and the sidewalk (Villanova Ave.).

… The on-road lanes worked best, the behind-parking lanes were the worst, and the adjacent paths were found to work in certain circumstances.

Notations from the City of Davis website says (retrieved 1/19/2017. Emphasis added):

Sycamore Lane Experiment: This 1967 bike lane used concrete bumpers to separate parked cars from the bike only lane. The parked cars screened the visibility of bicyclists coming into intersections and cars would unknowingly drive into the bike lane. This bike lane design was eventually abandoned.
The 1967 separated bike lanes on Sycamore Lane didn’t prevent conflicts with turning vehicles. Today at this intersection there are special bike-only traffic signals that provide cyclists their own crossing phase. These innovative bicycle signals were the first of their kind to be installed in the United States.

14 thoughts on “Cycle Tracks are NINE TIMES safer than roads?”

  1. Burrard St Bridge via google maps, here’s a street view.

    It is perhaps 1 mile long. It, being a bridge, and being elevated, and having no intersections whatsoever probably makes a fine place to put a cycle-track BUT IS NOT COMPARABLE TO A TYPICAL URBAN ROAD.

    Not sure of the timeline, though. According to a surprisingly detailed account on wiki a test of what sounds to be the cycle-track was “to begin in June 2009. The proposed trial began on July 13. It saw the southbound motor-vehicle curb lane and the northbound-side sidewalk allocated to bicycles, with the southbound-side sidewalk allocated to pedestrians. The reassigned lane was separated from motor vehicles by a physical barrier”
    Which seems like it doesn’t fit the timeline of the study very well which was for injuries presenting to the ERs “between May 18, 2008 and November 30, 2009”. Or at a minimum, it would have been a confounding factor.

  2. There were numerous letters-to-the-editor of InjuryPrevention raising criticisms to both the Lusk, and the Tesche article. You can find letters attached to a particular article by clicking on the original article’s hyperlink, and then scrolling down to “responses”. The M. Kary response is particularly compelling.

    Vulnerabilities of the case-crossover method as applied, and unsuitability of the epidemiological approach, to transportation injuries and traffic engineering problems – Part I
    M Kary, Mathematician
    Montreal, Canada
    Re: Comparing the effects of infrastructure on bicycling injury at intersections and non-intersections using a case–crossover design. Harris, et al. injuryprev-2012-040561doi:10.1136/injuryprev-2012-040561
    The case-crossover method in its familiar application is to look for factors that recur when cases occur, for individuals crossing exposure to them as examined over a time interval. This study [1-3] applies the method in a different way, the exposures being examined over a spatial route, with neither the identified factors nor the various routes being independent of the highly constrained urban geographies of the settings. Thus in addition to all the familiar vulnerabilities of the case-crossover method [4-10]– some of which require translation to the new context– this application brings new problems of its own. Overlayed on top of these is the general unsuitability of the epidemiological approach to transportation injuries and traffic engineering problems.

    These issues occur in abundance and deserve illumination, while replies are required to be brief. Consequently this is not a balanced assessment of strengths and weaknesses, but a spotlight on a selection of the latter. Even so this will have to be done over a series of eventual responses. I thank the authors for kindly providing extra information about their study as necessary for the following analysis.

    The case-crossover method is particularly vulnerable to recruitment and severity bias, information and recall bias, bias in the selection of control sites, temporal confounding of various sorts, and other problems [4-10]. It is also as subject as any other method to confounding by unmeasured, uncontrolled factors, and model dependence of adjustments for measured confounders. I focus on a few of these that take unusual forms in this study, even though there is reason to suspect that the others are at least as important. Examined in this first response are vulnerabilities to control site selection bias.

    For each site where an injury event occurred, the authors find control sites by randomly selecting another location along the route the rider took, from start to termination at the injury event. This is supposed to adjust for exposure to infrastructure types, the probabilities of their selection, and thus hopefully the resulting overall relative frequencies, being proportional to their relative lengths along the routes.

    To compare by facility types, intersections must be paired with other intersections, and likewise non-intersections with non-intersections. For injuries occurring at intersections, usually the location randomly chosen for use as a control will not land on another intersection, so the authors randomly adjust that location forward or back until it does. The authors have informed me that this was necessary about 70% of the time.

    In these instances, the selection of control intersections of various sizes (i.e., traversed widths) is dependent on their spatial distribution along the route, but indifferent to their widths. This allows their selection to be disproportionately biased in favour of smaller intersections associated to longer non-intersection segments. For example, over a route whose length is 30% intersections, 70% non-intersections, beginning at 0 and having terminated at 1, with intersections between 0 and 0.05, 0.5 and 0.6, and 0.85 to 1, the probabilities of choosing the three intersections as control sites should occur in ratios of 1:2:3. But by the authors’ adjustment method, in those instances where adjustment is needed, they are in fact respectively 0.5 x 0.45/0.7, [(0.5 x 0.45)+ (0.5 x 0.25)]/0.7, 0.5 x 0.25/0.7, thus occurring in ratios of approximately 1:1.56:0.56. Maclure [4] has discussed the potentially large biases in relative risk estimates that can result from not taking intersection widths into account.

    Likewise, sometimes the random location selected to control for a non-intersection injury event site lands on an intersection, so the authors randomly adjust that location forward or back until it doesn’t. In these instances (about 30%), this allows the selection of non-intersection control sites to be disproportionately biased in favour of whatever are adjacent larger intersections. This might very well have included cycle tracks, considering the ones in existence at the time of the study.

    There is though already a potential selection bias before this stage. Injuries almost always occur some distance before the very end of a planned trip. The authors restrict their selection of control sites to the route traversed before the injury event, thus systematically excluding the tails of the planned trips from selection. Bicycle facilities have particular distributions within cities and along routes (and over all routes in the sample considered as a whole), and consequently, excluding the tails of the planned trips may disproportionately bias the selection of control sites. For example, consider a route with no intersections, having a bicycle facility in the first and last thirds only. Suppose injury events occur completely at random along this route, so that they have no association with infrastructure type (or any other factor). The injury events therefore occur in bicycle facilities and non-facilities in proportions of 2:1, and likewise so should the selection of control sites. But an elementary calculation shows that, under the authors’ method of selection, the probability of the control being in a facility is [2+ln(4/3)]/3, so that instead the control sites occur in facilities and non-facilities in proportions of about 3.21:1.

    Some of the above vulnerabilities to bias are analogous to those familiar from meteorological case-crossover studies, where selection bias may occur if there are long-scale temporal waves of exposure, or serial autocorrelation. In the present context these correspond to spatial waves or autocorrelation of exposure, which occur both within routes and across subjects, the latter if only because the constraints of urban geography mean their routes may overlap. There can also be temporal waves or autocorrelations in the present study, e.g. for injuries occurring to different people during the same rush hour, in response to e.g. large scale spatio-temporal patterns of traffic congestion.

    Other studies have addressed such issues with more or less success by using bidirectional sampling. This and the resulting matter of selecting control sites post-terminating event has been discussed extensively in the meteorological literature on case-crossover studies [7-9], and by Maclure in the epidemiological literature [4].

    There is still another potential randomisation failure at this level of selection to consider. The standard deviation of the uniform distribution on [0, 1] is almost one-third (1/[2*SQRT(3)]). For individual runs of only 801 in length (for non-intersections), or 272 (for intersections), this can easily result in quintiles being out of balance by plus or minus 10 to 25%, which can again skew the estimates. (Thus the reader wishing to closely check by simulation the probability calculations given above should use a much larger n, such as on the order of 10^5.)

    This ends a first instalment, devoted only to control site selection bias. The next eventual instalment shall cover various other vulnerabilities to bias in this study, including the fundamental one introduced by considering only distance at risk, instead of or without the addition of time at risk [11].

    References
    1. Harris MA, Reynolds CCO, Winters M, Chipman M, Cripton PA, Cusimano MD, Teschke K. The Bicyclists’ Injuries and the Cycling Environment study: a protocol to tackle methodological issues facing studies of bicycling safety. Inj Prev 2011;17:e6. doi:10.1136/injuryprev-2011-040071.
    2. Teschke K, Harris MA, Reynolds CCO, Winters M, Babul S, Chipman M, et al. Route Infrastructure and the risk of injuries to bicyclists: a case-crossover study. Am J Pub Health 2012;Oct 18:e1-e8. doi:10.2105/AJPH.2012.300762.
    3. Harris MA, Reynolds CCO, Winters M, Cripton PA, Shen H, Chipman ML, et al. Comparing the effects of infrastructure on bicycling injury at intersections and non-intersections using a casecrossover design. Inj Prev 2013;0:18. doi:10.1136/injuryprev-2012-040561.
    4. Maclure M, Mittleman MA. Should we use a case-crossover design? Ann Rev Public Health 2000;21:193221.
    5. Redelmeier DA, Tibshirani RJ. Interpretation and bias in case-crossover studies. J Clin Epidemiol 1997;50;1281-1287.
    6. Sorock GS, Lombardi DA, Gabel CL, Smith GS, Mittleman MA. Case-crossover studies of occupational trauma: methodological caveats. Inj Prev 2001;7(Suppl I):i3842.
    7. Lee J-T, Kim H, Schwartz J. Bidirectional casecrossover studies of air pollution: bias from skewed and incomplete waves. Env Health Perspectives 2000;108:1107-1111.
    8. Bateson TF, Schwartz J. Selection bias and confounding in case-crossover analyses of environmental time-series data. Epidemiology 2001;12:654-661.
    9. Lumley T, Levy D. Bias in the case-crossover design: implications for
    studies of air pollution. NRCSE Technical Report Series NRCSE-TRS No. 031, 1999.
    10. Maclure M. The case-crossover design: a method for studying transient effects on the risk of acute events. Am J Epid 1991;133:144-153.
    11. Chipman ML, MacGregor CG, Smiley AM, Lee-Gosselin M. Time vs. distance as measures of exposure in driving surveys. Acciden Analysis & Prevention 1992;24:679-684.

  3. Flaws in the 2010 Lusk Montreal Study – streets with statistically significant results.
    Ian B Cooper
    Re: Risk of injury for bicycling on cycle tracks versus in the street. Lusk, et al. 17:2 131-135 doi:10.1136/ip.2010.028696
    1. Rue de Brebeuf Cycle Track vs. Rue St. Denis between Rachel and Laurier.
    These streets are not comparable.
    Brebeuf (which has a cycle track) is a narrow 40kph slow-moving one- way residential street with one traffic lane and one parking lane.
    Rue St. Denis (which has no cycle track) is a six-lane (two lanes often taken up by parking) 50kph limit two-way highway in a commercial area with lots of stores and distractions.
    It seems to me that more accidents will naturally occur on the six- lane highway with a faster speed limit. It’s unsurprising then that the study did indeed find a statistically significant advantage in terms of safety for Rue de Brebeuf. However, I would argue that this has nothing to do with the safety of the cycle track and everything to do with the very different nature of the roads compared…

    Published 7 August 2012
    Compendium of errors and omissions, or: What is not in this article
    M Kary, Mathematician
    Montreal, Canada
    Injury Prevention asks that responses to articles be kept to less than about 300 words. The volume of errors and omissions in this article by Lusk et al. is so excessive that it took me rather more than that– including photographs of the actual streets– just to document them. The result is now hosted on John S. Allen’s bicycle pages and can be directly found by searching the internet for e.g. these terms: compendium errors Lusk.
    A very small sample:
    -Authors report results for a path section that did not exist for almost the entirety of their claimed study period.
    -Errors of up to 100% in the claimed lengths of path segments, and thus corresponding errors in the reported rates of incidents per kilometre.
    -Biased selection of comparison streets… (much more)

  4. this is schadenfreude, but apparently last year Pucher predicted (mentioned below in a NYPost opinion piece) that CitiBike could cause bicyclist fatalities to triple in NYC. There apparently were 20/year in the pre-citibike period. Now the first full year crash results are in and there have been zero fatals (in 15Million miles of useage!)…

    Citi Bike ‘heading’ for a fall
    July 1, 2013 | 4:00am
    Mayor Bloomberg is often portrayed as an overprotective nanny, restricting cigarettes and soda sizes. So what about a bike-share program that lets novice riders loose on New York’s busy streets without helmets?
    About 20 cyclists are killed in accidents in New York City each year, but Rutgers University Professor John Pucher says the number of injuries and fatalities could triple in the Citi Bike program’s first year. So far, there have been reports of only three minor accidents involving Citi Bikes.
    Bloomberg spokesman John McCarthy says that the city has created hundreds of miles of bike lanes to protect cyclists and that enforcing helmet use would be impractical.
    Under state law, only delivery riders and children under 14 are required to wear helmets.

  5. “Protected” Lanes are anything but
    Catching up on paper-based reading this morning when I came across the “Between the Lines” column by Carolyn Szczepanski, Communications Director for the League of American Bicyclists, in issue 23 of Bicycle Times. This column is entitled “Staying Safe in Protected Lanes.”
    The column is remarkable, nearly Orwellian, for how it advocates for protected cycle tracks while illustrating all of the flaws that make them dangerous for all road users, particularly those cyclists to whom the “protected” lanes are most aggressively marketed, the so-called “interested but concerned” cyclists.
    Here are some excerpts that I am going to list in the order they appear in the column so you can see the bizarre juxtaposition.
    The column opens with this;
    “One minute, I was cruising down 15th Street in Washington, DC. The next, I was sprawled on the pavement, four cops peering down at me.”…

    Annotated article is linked in this CaD! thread.

  6. July 2015, gopro video of hit and run of driver making a bad left in Seattle; causing a straight going cyclist to collide with him. The 18 y.o. driver turned himself in soon after; no news on outcome. The driver was never named in the news apparently.
    The “protected” Bike Lane there tends to exacerbate all types of intersection collisions, which are the most common form of urban bike-mv crash.
    Dexter Avenue at Thomas Street, Seattle. This is a full-blown “parking protected” BL. Seems relatively recent, was perhaps new in mid-2015?
    What seems clear is the cyclist was going both “fast” (i.e. fast for a bicyclist) and well below the maximum speed limit (which i don’t offhand see, I would guess it’s 35mph). The cyclist, Trip Volpe reports his speed prior was 24mph, which seems accurate — judging speed from a wide-angle video is hard to do.

    This is, by the way, a combined RTO lane — that might not be the right technical name; I mean it’s a separated BL, then the separation ends on intersection approach where there’s a merge from the left, and is ultimately an RTO lane with sharrows and bicyclists exempted by sign. The treatment approaching the intersection appears to be exactly this NACTO design http://nacto.org/publication/urban-bikeway-design-guide/intersection-treatments/combined-bike-laneturn-lane/

    Somewhat related and coincidentally, bicyclist Mike Wang was killed in 2011 at this very intersection, by a hit-and-run driver driving an SUV, who also left-crossed the bicyclist. Erlin Garcia-Reyes plead guilty to felony hit-and-run and received the maximum 41 month sentence, INS has placed a detainer; which implies he will be deported after serving. It wasn’t clear why his sentece was so harsh, or if that’s normal for WA, or if the immigration status has something to do with it. Un-impaired (or cannot be proven impaired) hit-and-run drivers routinely pull very light sentences for fatalities they’ve caused.
    In 2011, the road was configured with standard, if door-zone, bike lanes.

  7. Explaining the Bi-directional Cycle Track Folly From Mikael Colville-Andersen at Copenhagenize

    “Bi-directional cycle tracks have a much higher risk to the cyclists than two, one-directional ones. The difference on crossings is about a factor 2. So, especially in areas with lots of crossings (ie. builtup areas), one-directional lanes are preferred. Not all municipalities get this message, however.”

  8. Cyclist Nusrat Jahan was killed at an Ottawa Canada September 2016 in a classic right-hook crash with a truck.
    This was a separated / protected bike lane, but of course that’s a misnomer since the lane is neither separated or protected at the intersection; a news story describes repeated experiences with right-hook conflicts. And though this is not a bike-box, it does contain a feature of bike boxes, which is the idea that bicyclists get a “head start”; this can work fine at the beginning of the cyclist-phase, but doesn’t help any later in the phase when all traffic including right-turning drivers have a green…

    Laurier at the intersection of Lyon, has a bike lane separated by a low concrete barrier to “protect” bicyclists. The green cycle starts with a straight ahead green arrow, so that bicyclists waiting on red can continue straight without conflict from right-turning traffic, but then the cycle shifts to a permissive solid green ball (as in this picture). Right turn conflicts are “handled” by a yield to bicyclists symbol sign (visible on the right side of this image). This lane opened to great fanfare in 2011, and presumably this is the first fatality at this location. Looking at the number of fatalities at one intersection is not a good way to measure facility design, since fatality rates at individual intersections are low, even with very dangerous designs.

    https://goo.gl/maps/kmFF7W3wBsH2
    CaD! discussion thread

  9. This has to do with 2-way cycletracks:
    Road Safety and Perceived Risk of Cycle Facilities in Copenhagen, Jensen SU
    “Taken in combination, the cycle tracks and lanes which have been constructed have had positive results as far as traffic volumes and feelings of security go. They have however, had negative effects on road safety. The radical effects on traffic volumes resulting from the construction of cycle tracks will undoubtedly result in gains in health from increased physical activity. These gains are much, much greater than the losses in health resulting from a slight decline in road safety.”

    See also Bicycle Tracks and Lanes: a Before-After Study, Jensen SU 2007, same paper available here.

  10. More on Ottawa; 2-way cycletrack left hook crash caught on video. Third reported crash on O’Connor Street cycle track since it opened only a few weeks ago.
    http://ottawacitizen.com/news/local-news/video-emerges-of-third-cyclist-hit-on-oconnor-bike-lanes
    See also Ottawa fatality Oct 2016 in a separated bike lane right-hook at Lyon & Laurier, above.
    Lane’s configuration rare: “these kinds of two-way bike lanes on one-way streets are rare in the province” and has some details on the other recent crashes on this cycletrack.
    Ottawa consultant’s report about O’connor two-way cycletrack.

  11. Special problems with any type of contraflow lanes are, or should be, well-recognized.
    Below research on counterflow bus lanes in Latin America:
    Our research indicates that counterflow lanes are associated with an increase in crashes at all severity levels (+83% fatal or injury, +146% pedestrian, +35% vehicle) … The main risk lies in the fact that counterflow is an unexpected configuration, and many road users may not anticipate vehicles arriving from a counterflow direction”
    https://www.citylab.com/transportation/2017/04/why-mexico-city-has-counterflow-bus-lanes/522471/?utm_source=SFFB

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