Category Archives: Bicycling

Is this an electrically-assisted bicycle?

Elf microcars, from Organic Transit Web site

Elf microcars, from Organic Transit Web site

The photo above is of ELF microcars from the US company Organic Transit.

The ELF is marketed as a velocar — an enclosed, pedal-powered vehicle — but in reality, it is an electrically-powered microcar designed to meet the legal definition of an electrically-assisted bicycle (or tricycle), the same way as a moped, by having vestigial pedals — and so to be street legal without meeting the requirements for equipment, registration and  driver licensing with a motor vehicle. The microcar is a viable concept, but whether microcars will succeed in the USA, or this one will succeed, is open to question. I do expect that the diversity of vehicle types will increase with time, as I’ve stated in an earlier post on this blog.

Most of the ELF’s power is from the electric motor. It can carry two or three people, or one person an a substantial amount of baggage, but only the one person in front has pedals. There is only a 3-speed geared hub for the pedaler, though a vehicle this heavy needs wide-range gearing if pedal-powered — so, again, the pedaling is secondary to the electric power.

The ELF can charge its battery from the power grid, or more slowly from sunlight, if there is sunlight. Claim is that the ELF travels as fast as most city traffic, but the top speed (limited by proposed electric-bicycle laws) is 20 mph. Legal to use on bike lanes or bike paths? Subject to mandatory bike lane laws? Open to question but it wouldn’t fit them very well — there are problems with microcars for disabled people in Amsterdam.

Claim “is much safer than a bicycle” is unsubstantiated, as the ELF hasn’t been around long enough to establish a safety record. Three-wheel vehicles are tippy and the people in the promo pictures are wearing neither seat belts nor helmets.

When slow is too fast

The basic speed limit, not to go too fast under the existing conditions, is often lower than the posted speed limit.

When facilities like the bike lane in the video are built in which 10 mph, or even 5 mph, is excessive speed, and, worse, when we are required by law to use them, then we get clobbered three ways. If we ride at safe speeds, the utility of bicycling for transportation and exercise is greatly reduced. If we ride faster than is safe, then we may crash, and be held at fault. If we avoid the facilities, we may be cited for not staying in our place, and harassed. And this, when bicyclists rarely can ride at the posted speed limit.

I’ll also quote my friend Mighk Wilson’s comments about the video:

It’s important to differentiate between “fault,” which is a legal matter for our purposes here, and “contributing causes.” If we only address fault we will usually fail to prevent crashes…

So who contributed to your crash? Obviously the motorist…he’s 100% legally at fault. But the designer of the bike lane also contributed, by leading you into blind spots where you’d be in conflict with turning vehicles. You yourself contributed by traveling at a speed at which you were unable to see, react and brake for the turning vehicle. Our bicycle advocacy groups contributed by insisting that bicyclists should always get to pass stopped motor traffic even when it’s risky to do so. Our land use planners contributed by allowing commercial driveways so close to major intersections. I could go on…

Part of the problem here is not only that the bike lane leads to blind conflicts, as Mighk points out, but also that it leads to false expectations of what is safe. I’d also add that planners, and lots of other people, contributed to causation of the crash by generating patterns of land use and mode choice which lead to traffic congestion. It is ironic that while it was only safe to travel at low speed in the bike lane, the traffic in the travel lane was stop-and-go, and had stopped completely. Whether a cyclist would have been able to travel safely at a higher average speed without a bike lane is open to question.

Lessons of Taiwan crash

The video embedded below of a car-bicycle collision in Taipei, Taiwan has been making the rounds on the Internet. When you have started the video playing,you can click on “Youtube”, and then on the little gear wheel at the lower right of the image to boost the resolution to 720 lines for the clearest view. Have a look, and then let’s discuss the lessons which this crash might hold.

First, let’s get some things out of the way. Where this video was posted  — by a Taiwanese media outletand in several other places — search on “Taiwan bicycle crash in crosswalk” and you’ll find them — there has been some wonderment that the cyclist on her bike-share bicycle landed on her feet. There have even been comments that the video  is faked. Well, it isn’t: if you look at it frame by frame, all the motion is continuous. There have been many comments about how nobody went to help the cyclist, and particularly about the callousness of the driver who checked his taxi after the bicycle glanced off it, but did not go to the aid of the cyclist. He does not come off well.

There have been recriminations against the driver whose car struck the cyclist — not deserved, as the cyclist was crossing against the light and concealed by stopped traffic. The driver swerved in an attempt to avoid her, probably saving her  from serious injury. The driver also stopped following the crash, but  the car is mostly out of the picture and the video cuts off too soon to show the follow-up.

There have also been many comments about how cyclists should not ride in crosswalks. I agree, if the crosswalks are alongside streets, but  in this case the crosswalk does not connect to sidewalks at a street intersection. Rather, it connects a path in a separate right of way where there are no turning movements by motorists. This crossing was properly signalized, too.

I think that the stopped, congested traffic misled the cyclist into thinking that  she could cross safely against the signal. Note the moving opposite-direction traffic at the far left of the picture: the street is a boulevard with a median. All the opposite-direction traffic should be on the other side of the median…but the roadway on this side of the median oddly has one lane for opposite-direction traffic — oops!

I see failure to obey traffic rules here, and not only by the cyclist: the  driver of the yellow taxi blows through a red light to cross the crosswalk, and the one whose  dashcam recorded the crash starts up on the red light while a pedestrian is starting to cross on a walk signal. The video ends before we see whether e dashcam motorist is going to stop, but it doesn’t look that way.

The cyclist puts a foot to the ground just before the car strikes her. That may have contributed to her remarkably ending up on her feet, but it isn’t a sign of good bike handling.

I expect to be accused of blaming the victim for posting these comments. That misses the point of this post, which is to offer some food for thought about how to avoid crashes. Obeying traffic signals is one of the lessons here, and another is not to ride blindly into a gap where there might be cross traffic.

I certainly hope that the cyclist did not suffer any serious injury, but I do see her as mostly at  fault for the crash. She is the victim, or to put it better, the vulnerable road user, in that she is the only person likely to have been injured in this crash, but she crossed against the light. What’s more to say, except that the opposite-direction lane created a trap which she evidently did not anticipate.

Europeans ride like this?

Check out this promotion video for Kickstarter funding, shot in Germany, or maybe Austria or Switzerland. The streets look German, and part of the narration is in German with English subtitles:

https://www.youtube.com/watch?v=pNs0ZQ_wzAc

The video shows three bicyclists. One of them is portrayed as a racer, and rides at speed on city streets. Here are three stills from the video:

At 0:31, our racer is riding in the door zone of parked cars, at high speed. It looks like he’s riding on the left side of the street but it’s the right side, where doors are more likely to open — driver’s side. The image is flipped: numbers on license plates are backwards, and the drivetrain is on the left side of the bicycle.

Bicyclist riding in door zone in flipped image

Bicyclist riding in door zone in flipped image

In the video, you’ll also see that he has just made made a left turn from the right side of a street where he also was riding in the door zone.

(This isn’t the only flipped clip in the video. Can you find the others? Weird!)

At 1.03 in the video, the racer is shown riding in the door zone, opposite the direction of traffic on a one-way street. Contraflow travel is legal on some quiet streets in residential areas in Germany, but then, this doesn’t look like that kind of street, and why ride in the door zone?

Bicyclists riding opposite traffic

Bicyclists riding opposite traffic

And at 2:13, our racer is shown making a right-hand turn into the door zone opposite the flow of traffic, at speed.

Wrong way

Wrong way

Northern European countries are often praised for including education about safe bicycling in the public schools. The popularity of bicycling in northern European countries is also supposed to improve cycling conduct there, through peer pressure. This video doesn’t fit that model. Can anyone explain why not?

You Gotta Be Kidding

The photo below is from MIT Spectrum, a publication of the Massachusetts Institute of Technology. The original caption reads:

Rotating between asphalt, grass and photovoltaic cells, spaces can dynamically shift from city street to park to energy source — on demand. If roads were solar panels, they could power 23.2% of Manhattan. Höweler and Yoon Architecture.

Image from MIT Spectrum

Image from MIT Spectrum

Uh, excuse me, but how did my alma mater, a well-known engineering school, sanction the fantastic collection of impractical ideas? The street is supposed to be made of motorized, three-sided rotating panels and one side is photovoltaic cells? How long would that hold up? Energy costs? Expense? There have been proposals for solar cells in glass block-surfaced pavers on walking surfaces, probably doable, though expensive; photovoltaics have even been suggested  as street paving — looks much iffier, but on the other hand, why would it make sense to put solar panels under the pounding wheels of vehicles in New York’s dark concrete canyons or even on rural highways when huge expanses of sun-drenched desert, or even New York City rooftops, stand open? Those wheely things over on the left of the picture? Aside from the difficulty of balancing and steering a monocycle, — it’s been tried (and you don’t have to go any farther than Wikipedia to see how impractical it is) — also, the rider’s pitching backward (“gerbiling”) in hard braking, how would one of these be stored in a New York apartment? It’s hard enough to store a folding bicycle!

 

Monsere, Dill et al. — Not Yet a Review, But…

M. Kary, who prepared a review of the Lusk et al Montreal study, has had a preliminary look at the Monsere, Dill et al. study of barrier-separated on-street bikeways (“cycle tracks”) which the bicycle industry lobby PeopleforBikes is promoting as demonstrating their safety. Dr. Kary has given me permission to publish his comments here.

An Introduction To and Overview Of:
Monsere C, Dill J, et al. (2014) Lessons From The Green Lanes: Evaluating Protected Bike Lanes In The U.S. Final Report, NITC-RR-583

To begin with a platitude: traffic accidents are rare events. The totals are large only because the overall volumes of exposure are huge. Therefore, if considering safety in terms of outcomes rather than the underlying mechanisms of operation, any facility, no matter how poorly designed, will appear safe if examined over a short period of time.

But collecting data over a long period of time has its disadvantages too: not just cost and delay, but also the averaging, and therefore blurring, of the effects of various changing causes and circumstances. Nor does it work at all for facilities that are yet to be built. In response to these problems, engineers developed the methods of traffic conflict analysis. They can be seen as based on the following logical and kinematic necessities. First, in order for a collision to occur, the vehicles involved must eventually get on a collision course. Second, in order to get on a collision course, they must first get on a near-collision course. On the other hand, not all vehicles once on collision or near-collision course do end up colliding: their operators make course corrections and avoid that outcome. Such potentially dangerous but often ultimately safe trajectories, i.e. traffic conflicts, occur much more frequently than actual collisions, deaths, or injuries. If there exists a suitable relationship between the former and the latter, then conflict analysis can be used to study road safety at reduced cost, with better timing, and even via simulation modelling of facilities that have been designed but not yet built.

The theory and practice of conflict analysis for motor vehicles has been developed over something like a half a century of research. This has evolved to quantitative methods using not just traffic cameras, but also instrumented vehicles, automated data extraction, and theoretical concepts such as time to collision, gap time, gap acceptance, post-encroachment time, and many others. There is no such corresponding body of research for bicycles. Even if there were, it could never be as important to bicycle or pedestrian deaths and injuries as it is for the occupants of cars and trucks: for example, the latter vehicles never topple over at stops or just slip and fall, so that their occupants fracture an arm or strike their heads on a curb. In fact the majority of bicyclist injuries, even those requiring hospitalization, apparently involve only the bicyclist, making conflict analysis entirely or at least largely irrelevant to them.

On the other hand collisions with motor vehicles are major factors in cyclist deaths and injuries, and they are what cyclists worry most about. And even apparently bicycle-only crashes can be provoked by e.g. general fears or specific intimidations, or avoidance manoeuvres leading to loss of control. Thus there are also dimensions of traffic conflicts applicable to bicycling, but either inapplicable or less so to motor vehicle-only conflicts. Nor is every conflict visible or strictly kinematic: consider for example the effects of sudden and loud horn honking or engine revving.

With these fundamental limitations in mind, obviously traffic conflict analysis is a promising method for investigating important aspects of bicycling safety. The theory needs to be developed, so we can figure out what constitutes a high or low rate of conflicts, what types of conflicts figure what way into which accident types, and how vehicle operators and pedestrians cope with them, such as through hypervigilance, or avoidance of the area and thus diversion of problems to a different one.

Not only does the theory need to be developed, but also the methods of data extraction and analysis: the subjective review of traffic camera recordings, typically of low quality, is a mind-numbingly tedious, labour-intensive and error-prone task, that does not scale well.

The work of Monsere et al. (2014), Lessons From The Green Lanes: Evaluating Protected Bike Lanes In The U.S., should be considered a pilot project in this effort, although the authors themselves do not describe it as such.

Monsere et al. aimed to address six questions:

  1. Do the facilities attract more cyclists?
  2. How well do the design features of the facilities work? In particular, do both the users of the protected bicycle facility and adjacent travel lanes understand the design intents of the facility, especially unique or experimental treatments at intersections?
  3. Do the protected lanes improve users’ perceptions of safety?
  4. What are the perceptions of nearby residents?
  5. How attractive are the protected lanes to different groups of people?
  6. Is the installation of the lanes associated with measureable increases in economic activity?

Apart from noting that, as with most sociological research, their survey response rates were dismally low (23-33% overall, counting even only partially completed surveys as full responses), to produce a socioeconomically skewed sample (e.g. the bicyclists being 89% white, 68% male, 82% having at least a four-year college degree, and 48% with annual incomes over $100,000)— this overview of their work considers only the first part of their question No. 2.

Monsere et al. installed video cameras along short bicycle sidepaths (“protected lanes”, “cycle tracks”) constructed between approximately the summer of 2012 and the early summer of 2013 as part of the Green Lanes Project. These were in four U.S. cities, San Francisco (two 0.3 mile paths), Portland (one 0.8 mile path), Chicago (0.8 and 1.2 mile paths) and Washington (a 1.12 mile path; no cameras were installed in Austin, although sociological surveys were conducted there). They did their video recording chiefly at intersections, six in these four cities in the summer and fall of 2013. This was then presumably while the users were still in a cautious or exploratory state, as they got used to the new facilities.

Only 12-18, or in one case 20, independent hours of video were analyzed from each intersection. As each intersection examined was given a unique treatment, results cannot easily be pooled. These are very small numbers.

(This makes for substantially less than 120 hours total. The authors seem to say they analyzed 144 hours of video at intersections. This would mean that some of this total came from multiple cameras examining the same intersection at the same time. The authors do show frame captures from some of their cameras. This observer would find it difficult to correctly identify the conflicts from the views on display.)

As noted following the opening platitude, any facility, no matter how poorly designed, will appear safe if examined over a short enough period of time.

The six facilities examined were all so new (less than or little more than a calendar year old) that there were no injury or death data available for them. (For comparison, the entire city and island of Montreal, with all its thousands of intersections, averages of late about five cyclist deaths and 25-50 police-recorded serious cycling injuries per year.) Thus, there would not have been a way to use even many more hours of recording to examine for any relationship between the surrogate outcomes (conflicts, violations or errant behaviours) and the outcomes of most interest, deaths and injuries.

Further, as this was neither a before-after study nor a comparison with standard intersections, there is no way to know whether the numbers of observed conflicts, violations, or errant behaviours, were themselves high or low.

As to the actual results from this pilot project, the much touted headline was that there were only six minor conflicts found, out of nearly 12,900 bicycle movements through intersections. The most basic problems with this headline are:

1. It is the wrong comparison. The conflict rate has to be the number of conflicts divided by the number of occasions where at least two users capable of conflicting are present, e.g. a bicycle and at least one other bicycle, pedestrian, or motor vehicle. Thus the authors give figures of 7574 turning motor vehicles, but only 1997 turning motor vehicles with bicycles present. The corresponding conflict rates (which they normalize by the products of bicycle and motor vehicle movements, not by the numbers of bicycle movements alone) they give for the individual intersections therefore vary by factors of approximately 3 to 10, depending on which figures are used.

2. Six is the total of observed “minor” conflicts, not the total number of observed conflicts. There were also 379 “precautionary” conflicts with motor vehicles, 216 with pedestrians, and 70 with other bicycles.

3. Besides conflicts, there were numerous violations or other errant behaviours: e.g. 9-70% of bicycles and 7-52% of turning motor vehicles in the various intersection designs used the lanes incorrectly, 1-18% of turning motor vehicles in the various mixing zone designs turned from the wrong lane, 5-10% of motorists turned illegally on red arrows at intersections with bicycle-specific signals, and 7-23% of bicyclists disobeyed their signals.

4. Without any theory or model of how any of these occurrences or their frequencies relate to death, injury, or property damage, and without any before-after or non-sidepath comparison data— not to mention, with the very small numbers of observation hours— there are almost no safety implications, positive or negative. The only concrete result is that one of the local authorities apparently deemed the problem of motor vehicles turning from the wrong lane (18%), straddling lanes (another 17%), or entering the turn lane early (15%) to be so severe that they later removed the intersection treatment and replaced it with another design (at Fell and Baker in San Francisco).

5. The sociological surveys tell another story: one-third of all bicyclists surveyed said they had been involved in at least one near collision on the paths, while 2% experienced an actual collision. 23% had a near collision with turning cars, 1.8% an actual collision with turning cars; 19% a near collision with a pedestrian, and 0.4% an actual collision with a pedestrian.

In short: this is an interesting pilot project, whose methods are impractical for the amount of data collection needed for meaningful safety results. Even with better methods, conflicts are only one facet of the bicycling, and overall safety picture; while road designers and road users, whether bicyclists or motorists, have to consider more than just safety. Convenience, transit time, cost, and greenhouse gas emissions also matter. A cycle track that, like the downtown de Maisonneuve track in Montreal, lies largely dormant in the winter, but delays motor vehicle traffic in the winter and ties it up spring, summer and fall, will be of no help in reducing CO2 emissions. The much touted headline results from this study are selective, overblown, and misleading. Any facility will appear safe if examined over a short enough period of time, and surely 12 to 20 hours each is short enough.

An Americanized Dutch intersection

The video embedded below was produced by Nick Falbo for a design competition at George Mason University. Mr. Falbo is now employed at Alta Planning and Design, a leading design firm which promotes and designs special bicycling infrastructure.

Protected Intersections For Bicyclists from Nick Falbo on Vimeo.

This is an impressive example of video art, but the video image and narration are far from telling a complete or unbiased story about the design. This article is an attempt to counterbalance Mr. Falbo’s claims.

The design is an attempt at a US version of one type of Dutch intersection. The Dutch traffic control devices (signs, signals and markings) have been replaced by US versions.

The video starts with an animation showing motorists and bicyclists all tailgating each other — unrealistic and fear-provoking. Conventional bike lanes and shared-lane markings are shown, and dismissed out of hand.

The accompanying narration says “sharing busy traffic lanes with cars is absolutely unacceptable” and “we know that protected bike lanes are the key to getting the average person to consider traveling by bike.” Like most absolute statements, these are inaccurate. The royal “we” invites the comment, “who, me too?” What other keys are we leaving off the keychain? Other infrastructure treatments? Decent weather, reasonable distances, secure parking, education, strict driver licensing and enforcement?

The video shows an intersection converted to the proposed design, losing right-turn lanes and so, traffic capacity — but that is never mentioned.

“Protected bike lanes” sounds inviting, but that’s inaccurate too: these are paths, not lanes. In traffic engineering, the word “protected” does not mean “bicyclists have a crossbike, the way pedestrians have a crosswalk.” It means that conflicting traffic movements are separated in time by traffic signals. Contrary to the title of the video, then, this is a protected intersection only if special signal phases prohibit motorists from crossing bicyclists’ line of travel — increasing delay. Except with these options, motorists must yield to bicyclists after turning the corner.

Pulling the bikeway away from the street so motorists must turn before crossing, as shown, does make it easier for motorists to see and yield to bicyclists overtaking on the right. That’s important because the design excludes normal merging before reaching the intersection: bicyclists and motorists must instead cross paths in the intersection. Crossbikes are, however, indicated feebly in the video only with dashed border lines, while the crosswalks behind them are indicated with bold zebra stripes. If more than one motor vehicle is yielding to a bicyclist, then all others behind have to wait.

The claim in the narration that “setback crossings provide the space and time for everyone to react to potential conflicts” is inaccurate. Motorists approach bicyclists from behind and to the left, so the bicyclists must either take it on faith that motorists will yield, or crane their necks and be prepared to stop.

Waiting space for bicyclists is limited. Walking becomes more challenging because pedestrians must cross the bikeway, then the street.

This video, its precursors and successors have also been discussed at length on Mark Wagenbuur’s BicycleDutch blog. Please read his blog post, and my response below.

Wagenbuur endorses Falbo’s design, though he criticizes Falbo’s explanation of some of its features, and quotes Dutch traffic engineer Dick van Veen about the waiting area for right turns: “It is right before the crossing place for people walking and cycling, but it is at the same time out-of-the-way from straight going motor traffic.” — a more positive interpretation of my own observation that if more than one car — or a long truck or bus — is waiting to turn right, then all traffic behind must wait.

Wagenbuur also goes on to criticize problems with various copycat versions of the Dutch design, and to point out alternatives. I agree with most of them but disagree with one claim, that a roundabout takes up less room than a conventional intersection. You might notice in the “before” overhead view in Wagenhuur’s blog post that one of the streets has a wide, landscaped median and the other appears to be located in a linear park. The extra space is taken up by bikeways which are set far back from the streets. The larger context of the intersection is visible here in Google Maps (before reconstruction, as still posted in June, 2014) and on Bing Maps (following reconstruction).

To sum up, Falbo’s video makes inaccurate claims, and also, the proposed design affects traffic capacity, delay, space requirements and safety in ways which he dismisses or ignores. Designs like this are buildable and politically feasible at some intersections in the Netherlands, where the political constituency for bikeways is strong, driver licensing and enforcement are very strict, motorists expect to yield to bicyclists on their right, and crossbikes are indicated with shark-tooth yield markings. To promote a design like this in the USA without considering the downsides and without those other criteria being met is to put the cart before the horse — to recruit citizens into an attempt to to force culture change through infrastructure change — but also to ignore many potential infrastructure alternatives such as Wagenbuur’s blog also discusses, ranging from creating a bypass for through motor traffic and reducing speed limits on bypassed streets, to grade separations, to identification of another quieter parallel street which would make a great neighborhood greenway.

PeopleforBikes promotes a new study

There hasn’t been time yet for a thorough review of the new study of barrier-separated bikeways on streets now being touted by the bicycling-industry lobbying organization PeopleforBikes, though claims of lack of traffic conflicts on these bikeways fly in the face of the experience of actually riding in them, and the results of earlier studies. The saying on the sign below is pertinent. Update, July 1, 2014: a quick “review preview” is now available.

The amount of energy necessary to refute bs is an order of magnitude bigger than to produce it.

A comparison

As is usual among advocates for such  bikeways, PeopleforBikes uses the feelgood propaganda term “protected bike lanes” for them — though they are technically paths, not lanes, and are unprotected where most car-bike crashes happen, at intersections and driveways. PeopleforBikes cites three earlier studies as setting the stage for the new one, and offers a tepid acknowledgement of criticism of these studies, with a link to criticism of only one of them, along with an appeal to groupthink, and while reiterating the studies’ conclusions:

Three widely noticed Canadian studies, led by Harvard’s Ann Lusk, the University of British Columbia’s Kay Teschke and Ryerson University’s Anne Harris, focused mostly on safety. And though all three concluded that protected bike lanes greatly improve bike safety (28 percent fewer injuries per mile compared to comparable streets with no bike infrastructure using Lusk’s methodology, 90 percent fewer using Teschke’s; in Harris’s study, protected lanes reduced intersection risk by about 75 percent), they’ve drawn some thoughtful criticism for underexamining the importance of intersections, where most bike-related conflicts arise.

The three Canadian studies which PeopleforBikes cites have been reviewed, in detail, and demolished.

The study Lusk, A. C., Furth, P. G., Morency, P., Miranda-Moreno, L. F., Willett, W. C., & Dennerlein, J. T. (2011). Risk of injury for bicycling on cycle tracks versus in the street. Injury prevention, 17(2), 131-135, claims a 28% lower crash rate for cycle tracks in Montreal, relative to comparison streets. Flaws of the study include describing stretches of paths in parks and away from streets as cycle tracks; including stretches which had not been built yet in the reported mileage; selecting a multi-lane comparison street 10 blocks away with heavy, faster traffic for comparison with a cycle track street which is small and has light, slow traffic, examining short stretches which end just short of busy intersections; giving the length of one of the paths as twice as long as it is, halving its reported crash rate, and neglecting injuries to pedestrians. A detailed rebuttal and a link to the study online may be found here. Another review reaches similar conclusions.

Teschke, K., Harris, M.A., Reynolds, C.C., Winters, M., Babul, S., Chipman, M., Cusimano, M.D., Brubacher, J.R., Hunte, G., Friedman, S.M., Monro, M., Shen, H., Vernich, L., & Cripton, P.A. (2012). Route infrastructure and the risk of injuries to bicyclists: a case-crossover ctudy. American journal of public health, 102(12), 2336-2343. has been reviewed and debunked by John Forester. The central problem is that the one facility described in the study as a cycle track and used for comparison with all the others is a bikeway on a long bridge separated by a Jersey barrier, with no cross traffic.

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 and Kay Teschke, Comparing the effects of infrastructure on bicycling injury at intersections and non-intersections using a case–crossover design, 19:5 303-310 doi:10.1136/injuryprev-2012-040561, has also been reviewed and demolished. The comments published on the Injury Prevention Web site are a condensed version of the ones published here and here. An explanation of how they came to be condensed is here. The authors oddly found bicycle-only paths in parks to be 17.6 times as dangerous as bicycle-only paths in (or adjacent to) streets. They find multi-use paths in parks to be 22.8 times as dangerous as bicycle-only paths in streets; and riding in the street to be 20 times as dangerous as riding in a bicycle-only path in the street. These results are bizarre and contradict those of numerous other studies.

Note that the authorship of these two studies overlaps.

Teschke gave a presentation at the 2012 Velo-City conference in Vancouver. I have posted comments on this presentation. My review addresses the deficits in epidemiology as an approach to the study of traffic safety, and also, specifics of the presentation. The graphics for the presentation display the preposterous result from the Harris study that bicycle crashes were 2000% as high on streets without cycle tracks as on streets with them, although the study also reports that more than half of all the crashes did not involve a motor vehicle. There are other absurdities. Also, it is clear from the authors’ presentation at a conference that they do not understand the definition of a collision, or intentionally skewed their data by describing single-bike crashes as collisions.

The authors of these studies flaunt their academic credentials, which may look impressive except when noting their errors of methodology and selection of data. These are not unbiased researchers: they are avid promoters of separate bikeways on streets, and the bias shows.

Fixie or track bicycle?

Track racing bicycle,from Bicycling Magazine

Track racing bicycle, from Bicycling Magazine. The caption in the picture reads “On a fixie, there are no gears or brakes. Only your legs control the drivetrain.”

From Bicycling Magazine, June 2014, page 28:

“A fixie (or fixed gear) is a singlespeed without brakes and without the mechanism that allows the bike to coast when you’re not pedaling.”

That is a description of a track racing bicycle, which is only one kind of bicycle with a fixed gear. The caption in the picture with the article repeats this description.

Let’s get definitions straight:

  • A fixed gear is a connection between the pedals and the driving wheel without a mechanism which allows coasting.
  • Antique high-wheeler bicycles have a fixed gear;
  • Children’s tricycles have a fixed gear;
  • Sturmey-Archer sells a three-speed fixed-gear hub, and so, some fixed-gear bicycles are not singlespeeds;
  • “Fixie” is not synonymous with “fixed gear”. Rather, “fixie” is slang for a bicycle with a fixed gear.
  • Fixed-gear bicycles for the road,  as a matter of common sense, safety and traffic law in many jurisdictions, must have a brake.

Though it is possible to slow a brakeless fixie by resisting the rotation of the pedals, this braking is not as effective as with a front handbrake, and can be lost due to the cranks’ outrunning the feet, or the chain’s coming off.

The photo with the Bicycling Magazine article shows a brakeless fixie on a street — illegal in many places, and with impaired safety due to the longer stopping distance and unreliability of braking. Also, the cyclist is using toe clips and tightly-adjusted straps with the end of each strap passed through the slot at the bottom of the buckle. The straps cannot, then, be adjusted while riding — OK on the track where a starter holds the bicycle upright, but not on the road. I have to wonder whether the cyclist in the photo was assisted in starting, or is being held upright for the photo by someone outside the picture.

Why am I taking the trouble to write this? Primarily, because the Bicycling Magazine article may induce people to take up riding fixed-gear bicycles without brakes on the road, and fumble with toeclips and straps, and crash, and be held at fault for crashing for lack of a brake. I am distressed that editors at Bicycling Magazine would pass on an incorrect description which generates confusion and might promote such behavior.

A thorough and accurate discussion of fixed-gear bicycles for use on the road may be found in Sheldon Brown’s article.

For the record, I own a fixie, shown in the photo below, and it is street-legal, equipped with dual handbrakes. If I had only one brake on this bicycle, it would be the front brake — but for riding with a freewheel, or on steep descents, I have installed a rear brake as well.

John Allen's fixie

John Allen’s fixie

Godzilla’s toothpaste decorates Seattle bikeway

A new bikeway has recently opened on Broadway in Seattle, Washington state, USA.

Someone has posted a video of a ride on the newly-opened bikeway.

(To get a better view of the video, click on “YouTube” and open it up full-screen.)

This is an uphill ride, very slow in most places. Traffic was light on the street, and even lighter on the bikeway. It will be interesting to see how the situation develops when traffic is heavier.

The bicyclist who made the video is clearly aware of the hazards, as he or she repeatedly checks for turning traffic before crossing intersections. Others might be more naive.

What most catches the eye though about this installation is the “Godzilla’s Toothpaste” barriers between the bikeway and parking spaces — an artistic touch, to be sure, though also a collision hazard, and sure to be pummeled by cars pulling into parking spaces. The toothpaste is visible a few seconds from the start of the video and also later.

As described by Seattle cyclist Joshua Putnam, the installation of the bikeway followed from a series of events, like a chain of dominoes falling over, except that some the dominoes were bicyclists. The first of these events was installation of a light rail line in the street. Then, bicycle crashes became much more frequent.

Light rail lines in streets are a serious hazard for bicyclists, from wheels’ getting caught in the flangeway, and from bicyclists’ having to choose their line of travel to avoid that risk. The problem is worsened by the tracks’ curving over to the edge of the street at stops — necessary so there can be a raised platform and wheelchair access.

To address the hazard it created with the trolley tracks, Seattle installed a two-way, one-side-of-the-street bikeway, on this two-way street. Such bikeways pose problems anywhere, due to the increased number of conflicts and unusual movements at intersections — but also much of Broadway is steep, and bicyclists traveling opposite the usual flow of traffic on the bikeway are going downhill. Crossing an intersection or driveway from right to left on the near side has been well-established as highly hazardous.

Before the trolley tracks, before the bikeway, bicyclists could travel downhill as fast as the motor traffic. Now, the safe speed is hardly more than walking speed, and with repeated checks for crossing and turning conflicts. As is the usual practice, large swatches of green paint have been spread on the street to demarcate zones where bicyclists and motorists operating according to their usual expectations are concealed from each other until too late to avoid collisions.

Motorcyclists also are at risk from the trolley tracks, but they are excluded by law from the bikeway.