City Cycling

Gasoline costs TRIPLE in the Netherlands, and Denmark
News item, Feb 2016 — Gasoline costs TRIPLE in the Netherlands, and Denmark compared to USA

My notations from the book: City Cycling edited by John Pucher and Ralph Buehler.

John Pucher is arguably the foremost American proponent of separate bicycling infrastructure; often called “Dutch-style”. He is an academic (planner-type; he’s not a traffic engineer) who has many published articles on the subject. And while he is a vociferous advocate for infra, if you read his work fully, he does at least mention there are other factors at play; and furthermore he considers these other factors as necessary to achieve high levels of safety and mode share a la Netherlands or Copenhagen. Among those other factors are, for example, the extremely high costs associated with motoring in those places with high bicycling mode share (duh). In the book, he covers these in the chapter Promoting Cycling for Daily Travel (see below). Here’s a brief excerpt where Pucher explains:

In short, such pro-bike ‘carrot’ policies [e.g. cycle tracks, bike parking] are indeed possible even in a car oriented country like the USA. By comparison, there is almost no political support in the USA for adopting and implementing the sorts of car-restrictive ‘stick’ policies listed in Table 3 [e.g. expensive fuel, high taxes, expensive vehicle parking, restrictive land-use policies] that indirectly encourage cycling in the Netherlands, Denmark and Germany.

Chapter: International Overview

Pucher has the same or similar table comparing fatalities/injuries for NL, DK, GER, UK,  USA (fig 2.6); i’m sort of confused by the injury rate calculations as I explained here in reference to another Pucher paper Making Cycling Irresistible: Lessons from The Netherlands, Denmark and Germany that was citing the same or similar data.

He also shows trends for a bunch of countries in fig 2.7 — it would be worth it to put that into Evan’s perspective of looking at the broader traffic safety picture internationally: Traffic fatality reductions: United States compared with 25 other countries in which Evans shows how badly the US is lagging in overall traffic safety compared to virtually the entire rest of the developed world. Continue reading “City Cycling”

Is it really 20 times more dangerous?

I’ve been seeing, more often lately it seems, fairly bold numerical statements about relative bike traffic safety; so to take this one from peopleforbikes for example (my emphasis added): “The problem is particularly glaring here in the United States, where bike injury and fatality rates are roughly 20 times those of the cycling-friendly countries of western Europe“. Continue reading “Is it really 20 times more dangerous?”

Helmet safety claims overstated

Thanks  to WABA : “The federal government is withdrawing its long-standing claim that bicycle helmets prevent 85% of head injuries, in response to a petition filed by WABA under the federal Data Quality Act.”

Congratulations to WABA (a Washington, DC, Area Bike advocacy group) for holding the government to account. While this, of course, is not going to end the “helmet wars”, it will hopefully move us back towards evidence-based investigation of bicycling transportation safety.

The particular US government agencies involved are the CDC and NHTSA who confirmed by letter they will stop disseminating the oft-quoted 85% figure. The NHSTA will, however, continue to claim helmets are “the single most important way to prevent head injury resulting from a bicycle crash”.

The WABA article is, by the way, a good explanation of what can go wrong with case-control type statistics that often are the output of public health community researchers. These types of claims are often(always?) behind the most stunning soundbytes, see e.g. cycle-tracks-are-NINE-TIMES-safer-than-roads.

Speaking of helmets, there was a recent long article in bicycling magazine; which is really interesting stuff about the current CPSC-mandated safety standards might be limiting advances that would allow different (different than the omnipresent EPS) materials, and better protection, especially from concussion.

Bike Share / CitiBike and helmets

One doesn’t imagine that bikeshare patrons often have a helmet with them, I didn’t when i visited Madison, WI summer of 2014 and partook of  B Cycle  there.

This is schadenfreude, but apparently last year Prof. 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 thefirst full year crash results are in and there have been zero fatals among CitiBike riders (in 15Million miles of useage!), and a total of 100 crash reports, i.e. a rate of 150,000 miles per incident…

Citi Bike ‘heading’ for a fall July 1, 2013
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.

Moving forward in time, NYC as a whole in 2015 reported 14 cyclist-MV fatalities, down from 20 in 2014.

WSJ editorial board member Dorothy Rabinowitz in an oddly-vitriolic tirade coins the term “all powerful bicycle lobby”; and mentions citibike may times in her bizzarre rant dated 5/13/2013. You just can’t make stuff like this up, here are my favorite excerpts:

“…New York’s best neighborhoods are absolutely begrimed by these citibikes…” “moderator: It’s not just shocking, it’s (presumably citibike racks) also a fire hazard in some cases the fire trucks can’t get into subway stations” “moderator (quoting car-ped crash stats): so is there a chance the danger is overblown? Rabinowitz: oh well look, before this (before, apparently referring to before citibike) it was dangerous, before this ever citizen knew, who is in any way senescent, that the most important danger (presumably to peds) in the city is not the yellow cab but the bicyclists who veer in and out…”.

She’s also mad that cabs have plaques admonishing passengers to not open their doors into traffic (which, i imagine is a legal requirement; it is in AZ).

Update on Citibike 6/12/2017: The first ever CitiBike rider fatality has been reported. CitiBike has been in operation in NYC since May 2013. Unhelmeted, it was dutifully reported. No word as to whether a helmet would have prevented the rider’s death. He was crushed to death by a 20+ ton bus. Police have said the cyclist “swerved”, however Gothamist reported surveillance video that surfaced later shows otherwise. NYPD have a track record of favoring motorists in bike-MV, or bike-ped collisions, e.g. Felix Coss was killed walking in a marked crosswalk with a green light, and NYPD says the pedestrian assumes the risk. Update 10/2018; the bus driver was convicted at trial of a misdemeanor and a violation,. See remarks at crash-not-accident. Video depicted the bicyclist going straight ahead (no swerve — where did that come from, did the driver lie to police?)

Divvy / Chicago Bikeshare

A Feb 2015 article in , my emphasis:”Divvy users have logged more than 3.2 million rides in the last 2½ years, and the small number of injuries suffered by riders may surprise skeptics, particularly because helmets aren’t required or even included with the rentals. But the Divvy data lines up with national statistics showing bike-sharing cyclists are generally safe, or at least lucky”  …Of the 18 reported incidents involving Divvy bikes, one involved a cyclist hitting a pothole, and another person suffered scrapes when the chain fell off a bike”.  Lucky? really? 3.2 million miles of luck? I don’t think they listed a tally, they mentioned a couple of what would be called “incapacitating” injuries; the most serious involved an apparently impaired divvy bicyclist.

In any event 3.2million/18 calculates out to one incident per 180,000 miles.

July 1, 2016 — Divvy Bike Rider Killed in Avondale Crash ID’d; Believed to be First US Bike-Sharing Death. Victim is 25 y.o. Virginia Murray. The article describes a classic right hook — according to the article there is surveillance video that showed the rider riding up the right side of a stopped flatbed truck (waiting at a signal I imagine); the truck then turns right, and collides with the bicyclist who was also turning (or intending to turn?) right. According the to the article the rider was wearing a helmet (which should be irrelevant, she was presumably crushed to death by the truck) but for the purposes here with bikeshares and helmets, I mention it.  According to the article there are a lot of “accidents” at this corner, and mentions — twice — “There are no bike lanes at the busy intersection”… underlying a misunderstanding of crash modes and right hooks. Bike lanes, if anything, exacerbate right hooks. A longer article on refers to the video, but hasn’t see it. A Chicago Bike lawyer has a description, but it sounds as though he hasn’t seen the video, either; he describes it as a standard right-hook and quotes a local ordinance stating an “overtaking” driver must yield to any bicyclist in such a situation (but was the truck driver overtaking?).

Phoenix / GRiD Bikeshare

A tidbit of very preliminary information was in councilwoman Thelda William’s newsletter:

Also, in November 2014, the GR:D Bike Share Program was launched. From January 1 to September 30, 2015, there have been 28,228 trips taken by 5,478 riders who have ridden a total of 48,583 miles. Since system launch, there have been very few operational problems, no bicycles have been lost or stolen, and there have been no reported traffic collisions involving GR:D bicyclists. Service continues to improve and expand.

BikeShare in general

newish (march 2016) study commissioned by CalDOT Bikesharing and Bicycle Safety, from the abstract, my emphasis:

Bikesharing has some qualities that appear inherently unsafe for bicyclists. Most prominently, helmet usage is
documented to be quite low in most regions… Finally, researchers conducted an analysis of bicycle and bikesharing activity data, as well as bicycle and bikesharing collisions to evaluate injury rates associated with bikesharing when compared with benchmarks of personal bicycling. The data analysis found that collision and injury rates for bikesharing are lower than previously computed rates for personal bicycling



This tidbit was interesting, I was unaware the BHSI was a sub-association of WABA, and interesting take about the slowing trend:

In 2013 the pace of new helmet laws has slowed to almost zero. Attempts to extend laws to cover adults have been unsuccessful. Urban riders are increasingly questioning the need for helmets, and certainly the need for helmet laws. WABA, our parent organization, has taken a position opposing the extension of the Maryland state helmet law to adults. A pendulum is swinging. We expect it to swing back eventually as injuries show up, but the positive experience with shared bicycle programs has raised basic questions about the need for helmets, and younger riders are reconsidering. We regard all that as a fashion trend and remain convinced that bike riders need helmets.

And their more general approach to mandatory helmet laws:

We have always been a lot more enthusiastic about promoting voluntary use of helmets than promoting laws, and it would appear from the list above that most U.S. states and localities are too. Even seatbelt laws that have been around for a long time are mostly secondary offense laws limiting enforcement to occasions when a driver has been stopped for something else. Helmet laws can be useful, but given the problems with enforcing them they will probably not work well in most places until more riders have accepted the need for wearing a helmet. So we favor a stronger push for voluntary usage than for passing new helmet laws, and our Web site has always reflected that attitude.

Some California Data

In spring of 2015, CA floated a mandatory helmet law SB192; put together some stats mostly about how rates of cycling over relatively large amounts of time have increased quite a bit; i.e. injury rate has dropped significantly. The bill ultimately got amended to replace the mandate with something about safety studies of helmet use.


It has been observed that Dutch cyclists have a very low rate of helmet usage, and at the same time enjoy a relatively low level of injuries and fatalities per distance traveled. See e.g. Pucher 2008 Making Cycling Irresistible: Lessons from The Netherlands, Denmark and Germany : quoting Dutch Bicycle Council figures “in the Netherlands, with the safest cycling of any country, less than 1% of adult cyclists wear helmets, and even among children, only 3–5% wear helmets”. Among mode-share advocates, it is believed that mandatory, or even high levels of, helmet use are detrimental to mode-share; there are various empirical and psychological explanations for this. With this grain of salt, consider this Dutch paper:

Overestimation of the effectiveness of the bicycle helmet by the use of odds ratios by Theo Zeegers  presented at International Cycling Safety Conference 2015 concluded  “Any case-control study in which the control is formed by hospitalized bicyclists is unreliable and likely to overestimate the effectiveness of the bicycle helmet”

Onestreet has a nice collection of factoids about the The Problem with Bicycle Helmets, and why “dangerising” bicycling is counter-productive.

Cycle Tracks are NINE TIMES safer than roads?

There was a glowing article in 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 about 9 times safer, 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. Interesting 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; 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. 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 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 in the late 1960’s as “experimental” designs, (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.

Perhaps telling, perhaps not, I have archived the .pdf referenced above as I can no longer find it on the website. There is a similar version of Buehler’s paper that was published through TRB with the same title (but with a co-author, Susan Handy); its conclusions are worded somewhat differently; instead of best and worst, they just say “Eventually all lanes were converted to the now familiar configuration of the bike
lane between the moving cars and parked cars” without saying why.

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.

Other Critiques

Ian Brett Cooper offers this critiques of a number of papers involving  segregated infrastructure, e.g.:

2012 Teschke: Route Infrastructure and the Risk of Injuries to Bicyclists: A Case-Crossover Study
Selection bias: uses comparison streets instead of a before-after situation; study claims greatly increased safety on cycle tracks, but the cycle tracks chosen for the study were not representative of a typical cycle track, in that all were on roads with limited or nonexistent road intersections. It is not surprising that bicycle facilities that have little or no possibility of interaction with motor vehicles are safer than those that have many such possibilities, and if all bicycle tracks were completely separated from turning and crossing traffic, they would indeed be safer than cycling on the road. The problem is, cycle tracks with few road intersections are very rare indeed.

2011 Lusk: Risk of Injury for Bicycling on Cycle Tracks Versus in the Street (Montreal, Canada)
The infamous Lusk study. Selection bias: study claims increased safety on bicycle specific infrastructure, but its street comparisons are flawed – the streets compared were in no way similar other than their general geographic location. Busy downtown streets with multiple distractions per block were twinned with bicycle tracks on quieter roads with fewer intersections and fewer distractions..


IIHS (2019) (#IIHS)

Some protected bike lanes leave cyclists vulnerable to injury

and the study page, more fully titled;

Not all protected bike lanes are the same: infrastructure and risk of cyclist collisions and falls leading to emergency department visits in three U.S. cities

Since Washington D.C. was a primary study site, and the home of a significant amount of separated bikelanes/cycletracks, The WashPo ran a news item on the study under the title D.C.’s oldest and most popular protected bike lane has ‘highest injury risk,’ study says, two-way cycletracks being unsurprisingly the most problematic.

As you might imagine, it’s generated quite a stir on certain discussion groups;, some thoughtful comments here:
 Highlights (part 1):
* Same “case-crossover” method as Teschke et al. Bicycling in Cities Study, which is the only reliable one yet used with N. American data.
* Unlike that study, there were actually PBLs installed in the cities where data was collected.
* They found NO safety benefit for one-way PBLs and a significant indication of higher risk with two-way PBLs.
* They reproduced the Teschke finding of higher risk for going downhill and VERY high risk due to streetcar tracks (all in Portland, OR).
Highlights, part 2:
* Only 40% of bicyclist injuries were due to moving motor vehicles (data are from emergency department visits).
* 12% of injuries were due to non-moving motor vehicles. These include dooring, but it is not presented separately. The figure rises to 20% of injuries on “major-roads.” They do not separate roads with and without on-street parking.
* Ordinary bike lanes appear to reduce risk BUT the presence or lack of on-street parking may be a confounding factor. The risk reduction is only AWAY from intersections. At intersections there was a 4-fold increase in risk (but not enough data to be statistically significant).
* Further, there was no evidence that bike lanes reduce the risk of collision with moving motor vehicles (see Table 6).
* There were only 18 injuries on one-way PBLs, which was not enough to determine how they affect risk EXCEPT that there was enough to say that they increase the risk of bike-ped injuries.
* Even with only 21 injuries on two-way PBLs, there was enough evidence to show that they increase risk by an order of magnitude, specifically collisions with bicyclists and pedestrians (Table 6).
The study is yet more evidence that looking at motor vehicle crash statistics (which ignore incidents not involving mvs) will not give a true picture of the safety effects of bike facilities.


Why cities with high bicycling rates are safer for all road users

Another Marshall and Ferenchak study Why cities with high bicycling rates are safer for all road users; was commented on in this letter by Paul Schimek. In the study, F&M claim safety-in-numbers was not shown, but that “Better safety outcomes are instead associated with a greater prevalence of bike facilities – particularly protected and separated bike facilities”. Schimek observse that they mixed “trails” (off-street paths removed from roadways) with true protected and separated bike facilities. He also points out “Third, a significant p-value does not imply a causal relationship. With 112,918 observations, it is not difficult to find coefficients that pass conventional significance tests”. (is that “p-hacking“?). As well as some other observations.

An earlier F&M paper originally titled The Relative (In)Effectiveness of Bicycle Sharrows on Ridership and Safety Outcomes seems to have used the same dense statistical techniques they say establishes their premise; it involves census tract block groups.