Tag Archives: Bicycling


The cyclist’s comment on this Youtube video: “This is why turn signals are important. Had she used a turn signal, I would have stayed back and let her turn. But because she didn’t use one, I assumed she was going straight.”

Let’s take a look into the situation.

The car was initially stopped, second in line at a traffic light. Then the light turned green. The cyclist was approaching in the separated bikeway from the car’s right rear, off to the side. As the motorist initiated her turn, the cyclist wouldn’t be visible in the motorist’s passenger-side rear-view mirror. The motorist would have had to turn her head sharply to the right to see the cyclist, but she needed to look ahead to steer and avoid other potential conflicts. Yes, she should have used her turn signal, but again, she was supposed to yield to the cyclist, not the other way around, and the location of the bikeway made it easy for her not to notice the cyclist.

What are solutions to this problem?

* Well, certainly, drivers should use their signals.

* Bicyclists need to be aware of these conflict situations, and it’s best not to make assumptions.

* Bikeways like this create the appearance of safety because they assuage “fear to the rear” but in urban and suburban areas, most car-bike crashes are due to crossing and turning conflicts, including the one shown in the video, the classic “right hook” — and also the “left cross” (car turns left into the path of an oncoming cyclist). This is a two-way bikeway on one side of a street and so it placed the cyclist farther outside the view of the turning motorist, and can also lead to “Left hooks” and “right crosses”. Germany no longer recommends two-way bikeways like this, as the safety record has proved to be especially poor.

* To avoid these conflicts, the bikeway needs an exclusive signal phase when other traffic doesn’t turn across it. But that will result in more delay for bicyclists and motorists alike. This bikeway also crosses driveways where the barrier is interrupted.

* A bikeway in a corridor separate from streets, a bike route on lightly-used streets, ordinary striped bike lanes or wide outside lanes avoid the problems with a separated bikeway.

The location, in Seattle, Washington, USA.

PeopleforBikes Interprets Boulder Data

Here’s a quick review of an article by Michael Andersen of the PeopleforBikes Green Lane Project about the City of Boulder, Colorado’s removing what he calls a “protected bike lane”. I prefer to call it at barrier-separated on-street bikeway, avoiding a value judgment. Let’s see what the article in fact establishes.

graph in streetsblog article

Graph in Streetsblog article

According to the graph (copied above) and numbers in the article, the installation achieved a major reduction in collisions between motor vehicles at the expense of a 2.5 time increase in motor-vehicle-bicycle collisions. The article states that bicycle volume went up by 54%, and so the car-bicycle crash rate went up by about 1.6 times. Most car-bike crashes in urban areas involve crossing and turning movements. Forcing motorists to cross a bikeway to enter a travel lane, and forcing bicyclists and motorists to start turns from the wrong side of each other, make these crashes more difficult to avoid.

But the story gets more interesting if you click on the article’s link to city data. The left pie chart at the bottom of the city-data infographic shows crashes per year before the installation and the right pie chart, crashes per week following the installation. There were, on average, 11.3 car-bike crashes per year before the installation and 3 in 8 weeks, about 20 per year, afterward. That comes out to an increase of about 1.7 times, but the afterward sample is very small (3 crashes) and seasonal variation isn’t accounted for. The comparison has no validity.

Now look again at the graphs in the article. they don’t accurately reflect these numbers. The “before” bar reports about 0.15 car-bike crash per week or 8 per year, not the 11.3 per year in the pie chart, and so the graph shows an increase in bicycle crashes even greater than the numbers would suggest .

So, to sum up, the article reports a reduction in car-car crashes, but a large increase in car-bike crashes — while defending the bikeway as “protected” and failing to note that there isn’t enough “after” data to produce any statistically valid comparison.

Oh, and there’s also this, on the second page of the infographic:

“The bicycle volume increase along the corridor is consistent with the increase the city typically sees when school is back in session.”

The cyclist counts, unlike the crash counts, are robust. About half the increase is attributable to the school’s being back in session, not to installation of the separated bikeway — a point which Andersen neglects to mention.

To sum up:

What does the article say about the safety of the Boulder facility? Nothing. No conclusion can be drawn from the data, but despite that the Green Lane Project shot itself in the foot with a graph showing a large increase in bicycle crashes.

What does the say about bicycle use? Maybe an increase of 20% or so due to installation of the bikeway, though some of that may only have been transferred from another street.

What does the article say about the quality of Green Lane Project journalism? I think that I’ve made my point but you can answer that for yourself.

Alice Swanson fatality, a right hook

Here is the intersection in Washington, DC, where cyclist Alice Swanson was killed by a right-turning garbage truck.

The Street View is from 2009, as close as Google gets to the year of the crash (2008). The big cross street is Connecticut Avenue. The little one before it is 20th Street NW. My recollection is that the garbage truck turned right into 20th Street, and Swanson probably assumed she could pass it safely because it would turn right onto Connecticut Avenue and the traffic signal was red. If you open the Street View in Google Maps and click on the clock at the upper left, you can go to Street Views from different times and see the intersection without a bike lane (2007) and with green paint (2014). The dashed bike lane stripes indicate that motorists are supposed to merge into the bike lane, but many do not and it may not even be possible with a large truck. Note also that parking extends close to the intersection — the last 20 feet or so are no parking, with a fire hydrant.

I get a hug during CyclingSavvy instructor training.

I have operated my bicycle essentially as a driver since 1978, when I read an early edition of John Forester’s book Effective Cycling. Since 1982, I’ve been an Effective Cycling Instructor, then League Cycling Instructor, in the League of American Bicyclists educational program, which got its start with Forester’s work.

In the 1980s, Forester’s instruction about road use was state-of-the-art. Over the years, there have been changes to teaching techniques and content, some for the better and some for the worse, some from inside the League’s program and some by individual instructors,  but I think that it is fair to say that there has been no systematic revision and upgrade to the content about bicycle driving.

On the weekend of March 3-5, 2017, I took instructor training in a different program, CyclingSavvy, in Orlando, Florida.

CyclingSavvy Instructor Training, March 4, 2017. Instructor Trainers keri Caffrey and Lisa Walker debrief instructor candidates following a "feature" -- a ride through a demanding stretch of roadway.

CyclingSavvy Instructor Training, March 5, 2017. Instructor Trainers Keri Caffrey and Lisa Walker debrief instructor candidates following a “feature” — a ride on a challenging stretch of roadway.

CyclingSavvy is a program of the American Bicycling Education Association, with an emphasis on urban cycling. In my opinion, CyclingSavvy classes are more focused and effective than the classes in the League of American Bicyclists program.

A CyclingSavvy class can be difficult for long-time League Cycling Instructors, in part because we have, well, ingrained ways of doing things. I took a CyclingSavvy class in August, 2011, in Portland, Maine. It was a bit of a rough experience. There were misunderstandings, especially on a group ride before the class: about lane use — at one point I asked “what are we doing this for?” and about the purpose of the ride. (My video camera setup is important enough to delay the ride start?) I came off that class with a lukewarm endorsement at best to work toward being an instructor.

In the years since then, I’ve been privileged to develop a closer relationship with CyclingSavvy, by reading materials online, attending two conferences and working on a CyclingSavvy edition of my Bicycling Street Smarts booklet (still awaiting publication as of this writing).

I’ve learned quite a number of things from CyclingSavvy that were new to me. To name some:

  • more assertive lane positioning;
  • group lane changes from the rear;
  • how to instruct novice cyclists so they will ride as an organized group;
  • waiting for the green light to turn right, so as to turn onto an empty street;
  • Turning into the destination lane for a left turn immediately on turning right;
  • plotting strategies for lane use with Google Maps;
  • teaching techniques effective in effecting behavior change;
  • time management when teaching.

I got a solid recommendation to go for  CyclingSavvy instructor training last October — studied up — it’s demanding! — and took the training, March 3-5.

At one time during the parking lot session of the training, I said: “I’m humbled with what I’ve learned that’s above and beyond what I already knew.”

Which is true.

Trainer Lisa Walker then  came over to me and gave me a hug.

I’ve been asked to describe what led to the hug. And this has been my explanation.

The takeaway from my experiences: I recommend that League Cycling Instructors, especially long-time ones, take special care to familiarize themselves with the differences between their practices and those of the CyclingSavvy program. That study can be illuminating, and can make the difference between failure and success in the CyclingSavvy program. You might get a hug too!








Self-balancing motorcycle

Road and Track magazine has reported on a self-balancing motorcycle from Honda.

How does the motorcycle balance itself? As shown in videos with the Road and Track article, the front fork is hinged so the front wheel can move forward, increasing trail — the distance of tire contact patch behind the steering axis. Then automated steering motions shift the mass of the machine and rider slightly side to side to maintain balance. The machine is also reported to be able to perform a conventional track stand, like those done by bicyclists — turning the front wheel at an angle to one side, and maintaining balance by propelling the machine forward and backward.

These capabilities require that the motorcycle have special control mechanisms, a computer on board to operate them, and sensors to report the machine’s orientation — which can be tricky on a single-track vehicle, because it can balance even when leaning into a turn. The Honda feature is described as for low speeds and when the motorcycle is stopped. That would avoid the issue with leaning. An internal-combustion engine would require a special and complicated transmission to drive the motorcycle subtly backward and forward on short notice.  In any case, electrical motors are needed to adjust the fork angle and make subtle steering corrections. An all-electric motorcycle is simpler and can be used indoors, as shown in the videos in Road and Track. They show no exhaust pipe.
In a discussion on Facebook, Jim Lindner wrote:

Extending the wheel base and fork angle gives the ability to move the mass of the engine right and left, a form of weight shifting they likely did not count. A motorcycle has a bit more mass than a bicycle improving the resistance to change, but with a little leverage or sudden shift of load I think this system’s ability to correct will easily be overloaded.

This brings up the concept of the  operational design domain: the range of conditions under which robotic features work. Automated-vehicle researchers and engineers use this concept. ODDs range from cruise control and anti-lock braking up through robotic crash avoidance for a vehicle otherwise under the control of a human driver, and onward to driverless operation under increasingly more challenging conditions.

The ODD for an automated two-wheeled vehicle does not include slippery surfaces or steering into a curb at a low angle unless it has sensors which allow it to avoid these hazards.  To avoid falling over, it must avoid these conditions as a skillful human driver would. This capability is far in the future.

Saddle research saddled with problems

Bicycle Retailer and Industry News has published an article describing and linking to a cycling and health study which focuses on saddle comfort and potential for injury due to pressure from the saddle.

During my cycling career, I have used about 20 saddles, some of which I don’t even remember. I currently own and using several bicycles. I was therefore unable to answer the questions about saddles. I currently own and use several bicycles. Also, there was no saddle shown which looked at all like the Brooks leather saddle which I favor. The assumption that a cyclist would have and use only a single saddle at any point in a cycling career, was in conflict with the question about different types of cycling (road, mountain, triathlon, spin class), which allowed multiple answers.

The “how many miles/hours do you ride per week” question did not account for seasonal and day-to-day variation.

I occasionally used to have some moderate and transient penile numbness after rides (75 miles and up) but the study offered no way to correlate the length of a particular ride with that. I don’t have the problem any more. Maybe I adjust my bike fit better.

All in all, the researcher would have benefited from some exploration of cyclists’ habits, to formulate the questionnaire better.

My favorite way to avoid problems with overuse injury when cycling, of which this is only one of many kinds? Listen to what my body tells me. What is the need to ride until it hurts? Perhaps I’m not obsessive enough! And now I see in Lester Binegar’s comment on the Bicycle Retailer site that the researcher has an agenda. Sigh.

About the bicycle radar reflector Kickstarter campaign

This is commentary about a Kickstarter campaign for a radar retroreflector integrated into a bicycle taillight assembly.

An image from the Web site:

Image from Ilumaware Web site

Image from Ilumaware Web site



One nice thing I can say about the product is that it is quite inexpensive, so I’ll say that first. The reason is that this is not a high-tech product. This is a low-tech component of a system whose high-tech component is in cars.

Retroreflectors work by concentrating light (or in the case of a radar reflector, radar signals) back toward the source. The product is a single cube-corner retroreflector. Optical retroreflectors are the insect’s eye version, with multiple smaller reflective elements, so they work at the much shorter wavelengths of visible light. The technology is described on another Web page.

As to the effectiveness of this product, I have no doubt that it improves the visibility of a bicycle to radar — but…

The product’s Web site repeatedly uses the term “OTR technology”, without ever spelling out the meaning of the acronym . I couldn’t find a definition anywhere online, either. This term makes the product appear more high-tech than it is. Indeed, the site claims:

Stealth techniques use radar reflection to make an object less visible and/or “invisible” to radar. We have reverse engineered this technique into a product used by a cyclist to make you more visible to a car. This is a revolutionary application of radar technology.

Reverse engineering is correctly defined as analysis of an undocumented product to develop specifications for a duplicate or similar product. Examples are the Wright brothers’ reverse engineering the flight characterisics of birds to design aircraft, and Linus Torvald’s reverse engineering the proprietary Unix computer operating system to construct the Linux operating system. The Kickstarter campaign uses the words “reverse engineered” inaccurately, so as to mislead people who do not understand it, as if to mean design of a product to have the opposite effect of an existing product. And when that product is a stealth bomber — wow, now the new product must be extremely high-tech! Again, the product is a simple cube-corner radar retroreflector, as has been used in boating for decades. The designers describe design and optimization of their product, but this is plain vanilla engineering, not reverse engineering.

A radar retroreflector which works in all directions is more desirable, (though it still will not always work, even if a car has radar, because the radar beam may not be aimed in its direction, and there may be a line-of-sight obstruction).

Radar alone as a robotic aid to a human driver is possible, but not very practical. Only a small percentage of cars have radar as of yet. A human driver uses visual cues. A fully-robotic car also must, because not every potential obstacle will be as large or reflect radar signals as well as a bicycle — think potholes, cats and dogs, etc.

The product, as shown on the Web site, includes an active taillight, but no optical retroreflector — though installed in the same location on the seatpost which is usual for one — following in the long tradition of new products promoted as a panacea for cyclists’ conspicuity problems while ignoring basic legal and functional requirements. Most states require a retroreflector or taillight, but any taillight can go out without the bicyclist’s being aware of that, and so any bicyclist who rides after dark should have a rear-facing retroreflector, not only a taillight.

The online promotion entirely fails to mention the need for a headlight, or the legal requirement for one. The Web site shows a bicycle with no headlight.

A bicyclist must always use a headlight at night, because an optical forward-facing reflector does not alert pedestrians or drivers who do not have headlights aimed at the bicycle (cars backing out of driveways, at stop signs in side streets, other bicyclists without headlights, etc.) Still, unlike the optical retroreflectors on bicycles, a forward-facing radar retroreflector is likely to be effective, because a car’s radar is likely to scan in more directions and its pulsed output is immune to interference from other sources. But the retroreflector here is only rearward-facing.

The online promotion also makes a number of inaccurate statements.

 Riding with a tail light [sic] is important regardless of the time of day.

While a very bright taillight can help to alert drivers — human or robotic —  during daytime, reducing the probability of a collision somewhat, there is no law requiring a taillight (or rear-facing optical retroreflector) when riding during daytime.

* “In 2015, more than 35,000+ collisions occurred between cars and cyclists in the U.S. Approximately every 3 minutes, world-wide, 6 people die and nearly 285 people are injured in collisions involving cars and bicycles. The majority of these accidents are from behind because drivers didn’t see the rider and it is NOT because they did not have a tail light.”

This is wildly inaccurate. While rural car-overtaking-bike collisions are disproportionately serious and fatal, only approximately 7% of car-bicycle collisions in the USA are car-overtaking-bike collisions. A very large percentage of these occurs to cyclists riding at night without a taillight! In urban areas, most of the serious and fatal collisions involve turning and crossing movements. No rear-facing conspicuity equipment —  optical or radar retroreflector, or taillight, will prevent most of these. Sure, many if not most car-overtaking bike crashes could be avoided, day and night, by use of a radar reflector, if cars have radar connected to a robotic crash avoidance system — but again, as of yet, only a very small percentage of cars is so equipped. Which takes me to my next quote:

* “In 2016 … there are 470 out of 566 unique car models sold in the U.S. equipped with radar (83%).”

This is very seriously overstated. Saying that a model is equipped with radar is not the same as saying that radar is standard. Adaptive cruise control is still often an expensive option. Only some adaptive cruise control systems include automatic crash avoidance. Some systems use laser ranging rather than radar. The fleet of motor vehicles turns over slowly. More even-handed estimates are found in this article in the Detroit News. Quote from that article:

IHS Automotive forecasts 7.2 percent of vehicles produced globally by 2020 will feature adaptive cruise control, up from 2.2 percent in 2014.

More details and a list of vehicles are on Wikipedia.

Why do promotions like this occur? Fundamentally, because regulation of bicycle equipment in the USA at the Federal level, where equipment standards are set, is a Wild West situation, harkening to the interests of the bicycle industry. That is another story, too big to cover here.










Boston expert design

Here’s a video of the intersection of Commonwealth Avenue and St. Mary Street, Boston, Massachusetts, USA, an example of the design expertise which earns Boston its place with the League of American Bicyclists as a Bicycle Friendly City.

The video is from 2013. As of 2016, one change has been made: the zigzag in the bike lane has been replaced by a diagonal transition.

The idea that cyclists should turn across in front of multiple lines of motor vehicles to change lane position is not unique to this location. Here’s another example, and it is by no means the only other one:

I have a blog post in connection with that video too.

Montreal sidepath protects?

A classic right-hook collision occurred on August 26, 2015 in Montreal, where the cyclist was riding on a sidepath.

Here’s a news report on the crash.

As I’ve said repeatedly, sidepaths do not prevent crossing and turning collisions.

The sidepath in this crash is in a block folliwng a steep downhill. The cyclist might have been  overtaking the truck which turned right across his path.

I have cycled through the crash location and shot a video of my ride. It is here.

Rue Berri from Cherrier to de Maisonneuve, Montreal from John Allen on Vimeo.

Michael Colville’s Pitch

About the video here by Mikael Colville of copenhagenize.com:

Mikael Colville’s talk in the video is introduced by a video clip of a rather sorry infrastructure situation, with a crowd of bicyclists slowly making their way forward, cramped in a narrow passage to the right of an opaque barrier, while a line of cars turning right must yield to the cyclists after turning past the barrier. To me, this choice of a clip conveys the message “look, we are morally superior, motorist, we’re going to make it hard for you: you have to yield to us.” It doesn’t say anything about making bicycling more convenient, or anything but a nuisance to people who might think of switching from motoring. Or that whoever chose this location had any other sense about infrastructure — certainly none about sight line hazards.

And the music — the Rolling Stones’ Sympathy for the Devil! Now there’s an odd choice!

Similarly, at the end, there is an overhead drone shot of a bridge which has recently been restriped from four to two lanes of motor traffic, to add street level bike lanes next to already existing bikeways behind curbs. The implication is that bicyclists are winning by taking space away from motorists, and that space is to struggle over, not to share. In this case, on a bridge, I’d agree that bike lanes are suitable, but are four needed? What happens where they turn off at the end of the bridge while motor vehicles can go straight? We don’t see. Who knows?

The talk is all about marketing. The core of his message is that guilt-tripping people about environmentalism doesn’t work, and we must use marketing to make bicycling look attractive. Two products which Colville discusses for purposes of comparison, sewing machines and vacuum cleaners, are both highly useful labor-saving devices which quickly became popular for that reason, but he doesn’t mention that. He does praise improvements which made them more compact and useful in the home, but mostly, he praises the decorations on sewing machines which made them more attractive to homemakers.

My mother owned a Singer treadle sewing machine, and indeed it was a beautiful product — to some degree because of the flower stencils but also because of its elegant product design, with a table to hold supplies and attachments, and into which the machine could be folded down to make the table useful when the machine wasn’t in use. Treadle power was perfect for the pre-electrical era, and the wheel on the right end of the machine could start, slow or stop it with precision. Not to speak of my mother’s machine’s being several decades old and still working perfectly.

My mother also owned a 1950-ish Kenmore (Sears brand, made by Electrolux) vacuum cleaner, and it was an esthetic horror, shaped like an airplane fuselage, painted dull gray and very loud. She made much more use of the vacuum cleaner than of the sewing machine.

Colville says that we must market bicycling like these products. He deprecates “the 1%” of people who will wear fancy cycling clothing” — guilt by association with political class struggle, divisive, and also a reference to the categorization which Roger Geller made up, pulling the numbers out of his head, only to be followed up by a home-town study which found that his numbers were exactly right (surprise!).

Colville says that people are conservative and don’t want to stand out. But, tattoos peek out from under his plain white T shirt.

I don’t think that bicycling can be sold by marketing alone. It must be practical and useful like a sewing machine or vacuum cleaner, or people won’t use it for daily transportation. Though some people like to show off with Spandex and carbon fiber bikes, others wear street clothes and ride beater bikes. Some do both. Should instructors even care? We make bicycling more practical for any cyclists by helping them to do it well — and offering informed opinions on what works, or not, in bicycle planning and infrastructure.