23 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. Some elaborate striping; e.g. City of Memphis Tennessee… the scheme to mitigate right hooks: a “mixing zone” becomes a combination vehicular RTO lane and thru-bikelane (is this “legal”? maybe it’s one of those experimental deals? is this out of NACTO?):

   http://bikepedmemphis.wordpress.com/2013/08/20/memphis-constructing-first-protected-bike-lane/

5. 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.

6. Pingback: Helmet safety claims overstated | Arizona Bike Law

7. This is a fragment copy/pasted from a Facebook post from Jack Warman in 2013:
   —
   “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 (private group, membership required)

8. 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.

9. 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.”

10. 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

11. 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.

12. 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.

13. Seattle PBL / cycletrack collision story:

    https://www.reddit.com/r/Seattle/comments/5pj8ec/last_night_the_protected_bike_lane_nearly_killed/

14. 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

15. 11/20/2016 bike-bike fatal crash (one fatal, one serious injury)
    Balboa Ave east of Clairmont Dr, San Diego (or maybe actually Clairmont?) The Google maps link is approximate. Note that plastic flex-posts were added after the latest google street view.
    Both bicyclists were going same direction and one passed the other; the two were unassociated; i mean they did not appear to know each other, and weren’t riding together. nbcsandiego.com Names were not released.
    Here’s a news item about from July 2016 the road treatment, flex-posts were placed on May 24, 2016. The road formerly was a 4 lane divided highway with shoulder and guard rails; the 4 lanes were narrowed a bit and shifted to create space for a left-buffered BL with (many) flexposts (one every 10 feet?) placed in a buffer area between the travel lane and the BL.
    This fits the description of what the FHWA calls a “separated Bike Lane”.
    This crash, injury, and even the fatality will not appear in FARS or other traffic stats (well, i mean presumably) since it did not involve a motor vehicle, it’s a “non-traffic” crash.
    It appears this may be a signifcant downhill grade, and perhaps the crash we so severe due to high (relative) bicyclist speeds.
    There was a little discussion of the incident in a f.b. group.

16. queries related this statement in the IIHS study:
    — quote —
    Most fatal bicycle-motor vehicle crashes occur midblock away from intersections (Insurance Institute for Highway Safety, 2018), and protected bike lanes are built primarily to shield cyclists from
    this dangerous crash type.
    — endquote —

    The stat they refer to is given in their reference as 36% intersection, and 64% non-intersection(which they note includes unknown and “other”).

    When looking at only Urban, the figure shifts, but not a whole lot, it’s 59% Non-intersection.
    i.e. (323 + 7) / (178 + 50 + 323 + 7) = .591
    2017 FARS data.

    
    SELECT sUrbanRural, eBIKELOC BikeLoc, count(*)
    FROM ((( 2017_incident as i JOIN 2017_person AS p_bike ON (i.ST_CASE = p_bike.ST_CASE AND p_bike.eINJ_SEV LIKE ('Fatal%') AND p_bike.ePER_TYP IN ('Bicyclist', 'Other Cyclist') )) 
    JOIN 2017_vehicle as vehicle ON (i.ST_CASE = vehicle.ST_CASE AND vehicle.VEH_NO=1 )) 
    JOIN 2017_PBType AS pbtype ON (i.ST_CASE = pbtype.ST_CASE AND p_bike.PER_NO=pbtype.PER_NO)) 
    WHERE 1=1
    GROUP BY 1,2;
    
    SELECT count(*) "total bicyclists in fatal crash"
    FROM ((( 2017_incident as i JOIN 2017_person AS p_bike ON (i.ST_CASE = p_bike.ST_CASE AND p_bike.eINJ_SEV LIKE ('Fatal%') AND p_bike.ePER_TYP IN ('Bicyclist', 'Other Cyclist') )) 
    JOIN 2017_vehicle as vehicle ON (i.ST_CASE = vehicle.ST_CASE AND vehicle.VEH_NO=1 )) 
    JOIN 2017_PBType AS pbtype ON (i.ST_CASE = pbtype.ST_CASE AND p_bike.PER_NO=pbtype.PER_NO)) 
    WHERE 1=1;
    
    SELECT sUrbanRural, count(*)
    FROM ((( 2017_incident as i JOIN 2017_person AS p_bike ON (i.ST_CASE = p_bike.ST_CASE AND p_bike.eINJ_SEV LIKE ('Fatal%') AND p_bike.ePER_TYP IN ('Bicyclist', 'Other Cyclist') )) 
    JOIN 2017_vehicle as vehicle ON (i.ST_CASE = vehicle.ST_CASE AND vehicle.VEH_NO=1 )) 
    JOIN 2017_PBType AS pbtype ON (i.ST_CASE = pbtype.ST_CASE AND p_bike.PER_NO=pbtype.PER_NO)) 
    WHERE 1=1
    GROUP BY 1;
    
    SELECT eBIKELOC, count(*)
    FROM ((( 2017_incident as i JOIN 2017_person AS p_bike ON (i.ST_CASE = p_bike.ST_CASE AND p_bike.eINJ_SEV LIKE ('Fatal%') AND p_bike.ePER_TYP IN ('Bicyclist', 'Other Cyclist') )) 
    JOIN 2017_vehicle as vehicle ON (i.ST_CASE = vehicle.ST_CASE AND vehicle.VEH_NO=1 )) 
    JOIN 2017_PBType AS pbtype ON (i.ST_CASE = pbtype.ST_CASE AND p_bike.PER_NO=pbtype.PER_NO)) 
    WHERE 1=1
    GROUP BY 1;
    
    SELECT eBIKECTYPE "CrashType Non-intersection", count(*)
    FROM ((( 2017_incident as i JOIN 2017_person AS p_bike ON (i.ST_CASE = p_bike.ST_CASE AND p_bike.eINJ_SEV LIKE ('Fatal%') AND p_bike.ePER_TYP IN ('Bicyclist', 'Other Cyclist') )) 
    JOIN 2017_vehicle as vehicle ON (i.ST_CASE = vehicle.ST_CASE AND vehicle.VEH_NO=1 )) 
    JOIN 2017_PBType AS pbtype ON (i.ST_CASE = pbtype.ST_CASE AND p_bike.PER_NO=pbtype.PER_NO)) 
    WHERE eBIKELOC LIKE 'Non-intersection' 
    GROUP BY 1  ;
    
    SELECT eBIKECTYPE "CrashType in Intersection", count(*)
    FROM ((( 2017_incident as i JOIN 2017_person AS p_bike ON (i.ST_CASE = p_bike.ST_CASE AND p_bike.eINJ_SEV LIKE ('Fatal%') AND p_bike.ePER_TYP IN ('Bicyclist', 'Other Cyclist') )) 
    JOIN 2017_vehicle as vehicle ON (i.ST_CASE = vehicle.ST_CASE AND vehicle.VEH_NO=1 )) 
    JOIN 2017_PBType AS pbtype ON (i.ST_CASE = pbtype.ST_CASE AND p_bike.PER_NO=pbtype.PER_NO)) 
    WHERE eBIKELOC LIKE 'Intersection%' 
    GROUP BY 1  ;

17. Comments from pucher and buehler regarding iihs PBL study

    https://www.forbes.com/sites/carltonreid/2019/08/22/leading-u-s-bicycle-safety-academics-question-protected-cycleways-are-risky-study/amp/

18. Review of Columbus Summit St bike lane / Patricia Kovacs
    https://drive.google.com/file/d/1nipFKhMJeGlMblxDTybx9Ly-c3r0Icc5/view

19. https://www.youtube.com/watch?v=lYsO1uvL5MA

    There’s a newer”explainer” type video; Bike Lanes Have A Deadly Design Flaw – Cheddar Explains The flaw, of course, refers to right hooks (a.k.a. “coffin corners”). They refer to Tesche 2021, heralding the 90% reduction (OR .11 as explained above).
    The warning about right-hooks is important, but probably obvious to anyone that rides a bike. Other claims bear more scrutiny, like the claim that cycle tracks reduce (car-bike) crashes 90%; the video references a 2012 study by Teschke which can be found the article above. The trouble with that was the only cycle-track segment studied had no intersections. Cycle tracks work fine when there are no intersections, and poorly when there are intersections. Most urban situations have many intersections.

20. I “tweeted”:
    Raised separation elements aren’t always helpful or even benign

    in response to:
    https://twitter.com/bkevenides/status/1516795327768113154
    “Yesterday we achieved a jury verdict against the City of Chicago for failing to maintain its bike lane at 745 N Milwaukee (photo). Our client struck the base of a broken post (below) in 2016 & sustained a “shattered” kidney. Verdict exceeded $287,000″

    Today Riley tweeted a 45 second video of a very new project with “armadillos” as the separation element:
    https://twitter.com/rmerline1/status/1521882007667576832
    The project is on Main Ave in Tucson between Speedway to the north and 4th St to the south — about 1600′. LOTS of intersections/driveways… I counted 10 in the 45 second video.
    https://goo.gl/maps/FVPHkquS4x6X38YZ9

21. Armadillo injury story from Miami; being on a scooter probably magnified his injuries, but these devices are likewise dangerous for cyclists. Fall hazard.
    https://www.miaminewtimes.com/news/miami-beach-man-venetian-causeway-armadillos-caused-scooter-accident-14572227

22. https://www.forbes.com/sites/dianafurchtgott-roth/2022/09/08/bike-lanes-dont-make-cycling-safe/

    Ukraine/
    Diplomat killed by (right hook) turning commercial vehicle
    Washington DC
    Bike lane

23. (still draft as of August 2023; but pretty far along, and well footnoted)
    The Safety of Separated Bike Lanes: a Review of the Evidence
    Paul Schimek, Ph.D.
    Abstract
    This study reviews the evidence on the safety of urban separated bike lanes (SBLs). Several studies comparing SBLs to streets without any designated bicycle facilities were identified. After reviewing the studies, it was determined that only four used a valid methodology and had sufficient and relevant data. All of these found a negative effect of SBLs on bicyclist safety. Based on these studies, the best estimate is that one-way urban SBLs increase bicyclist injury crashes by 24% at intersections and by a lesser amount overall. Further research on SBLs is recommended, either by interviewing injured bicyclists or by studying road user conflicts through computer-analysis of videos, rather than relying on official crash reports.