Tag Archives: bicycle

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 be 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.

Duck Boat crashes

We had a duck boat run into a motor scooter from behind on Saturday, May 7, 2016 in Boston, killing one of the riders. It isn’t clear from the news story why this happened, though I expect that the poor forward visibility from the duck boat was a factor. Did the motor scooter operator pull ahead of the duck boat, riding and stopping in its large blind spots? Or did the duck boat operator run into the back of the motor scooter in spite of its being in hiss field of view? As usual with crashes involving two-wheelers — bicycle, motor scooters, motorcycles — and despite there having been many eyewitnesses, the Boston Globe offers no information as to the cause of the crash. Investigation is underway, although if it proceeds as with recent bicycle crashes, detailed results may not be made available for a long time, if at all.

Another duck boat crash occurred in Seattle, 5 killed, 62 injured — but that one was due to failure of an axle, which sent the duck boat into the side of a bus in an oncoming lane of traffic.

What is to be learned from these crashes?

For one thing, the duck boats are surplus from the Second World War. Though they served gallantly in that war, they are over 70 years old now: mechanical failures are not out of the question. The duck boats’ design as amphibious vehicles placed the driver high above the road over a high hood, with poor visibility to the front — a problem which has led to fatalities of pedestrians in crosswalks with large trucks. The duck boats do not have a front bumper, but instead, have a hull which can push unfortunate pedestrians, cyclists and vehicles underneath. These vehicles probably would not be legal, except that they are antiques.

Another issue with the Boston crash may be of education. Did the motor scooter driver not understand the peril of riding in blindspots of large vehicles? Boston is relentlessly installing bicycle facilities which direct bicyclists to ride into blindspots. It does not appear that the collision involved any such installation, but motor scooter operators are permitted under the law to use them, and their existence, along with a lack of instruction as to their perils, contributes to hazardous behavior elsewhere as well.

In the context of all these issues, my misgivings about the Vision Zero campaign described in the Boston Globe on April 17 need no further mention.

The Slow Ride, redux

Bob Sutterfield writes:

I don’t ride fast so I can participate safely in traffic. I participate in traffic so I can safely ride fast enough for my needs.

If I were to ride in the gutter, on the bike path, in the door zone, on sidewalks and cycle tracks, etc. I could reduce my risk (probably to an acceptable level) by traveling slowly – at near-pedestrian speeds. That slower speed would give me more time to react to the hazards present in those environments.

But I use my bike for purposeful travel. I don’t have time in my day to travel as far as I need to go, if I were constrained to moving only at near-pedestrian speeds. In order to get where I’m going in a practical amount of time, I need to be able to ride at the speeds I’m capable of sustaining on a bicycle. And I need to do it more safely than if I were in the gutter or on a bike path or in the door zone – I need the safety and convenience of the travel lane. That speed is what the travel lane is designed to accommodate, and that’s what the ordinary traffic laws are designed to enable.

If my choice of travel by bicycle is restricted to hazardous areas like gutters and bike paths and cycle tracks, I’ll choose another way to travel – something motorized so I don’t suffer those restrictions.

Lane Control on Lexington Street

Here’s a video showing a bicycle ride on a constant mile-long upslope, at speeds of 10 to 12 miles per hour (16 to 20 km/h), on a suburban 4-lane speedway with narrow lanes and no shoulders, the most challenging street in the community where I live. Motor taffic was very light, and auite fast. Points made:

  • Lane control is not about riding fast: it is about controlling one’s space.
  • Lane control is necessary so motorists will overtake at a safe lateral distance on a street with a narrow right-hand lane.
  • By requiring motorists to make full lane change, lane control lets a cyclist with a rear-view mirror confirm well in advance that motorists will overtake with a safe lateral distance.
  • With the light traffic on a multi-lane street, a slow bicyclist does not cause any significant delay to motorists.
  • Most motorists are cooperative.
  • A few motorists are abusive — even though they can easily overtake in the next lane —  but they too overtake safely.
  • American traffic law supports lane control.

Lane Control on Lexington Street from John Allen on Vimeo.

Bruce Epperson’s observations on transportation funding

Bicycle historian Bruce Epperson has written a paper examining trends in transportation funding in the USA from the 1960s to the present. It makes interesting reading. With his permission, I have made the paper available in PDF format on this Web site:


M. Kary on the epidemiological approach to traffic-safety research

M. Kary has released the manuscript of his paper on the unsuitability of the epidemiological approach in studying traffic safety.

Unsuitability of the Epidemiological Approach to Bicycle Transportation Injuries and Traffic Engineering Problems
Author: M Kary
Injury Prevention 2015;21:73-76, Published Online First 14 August 2014

First paragraph of the abstract:

Bicyclists and transportation professionals would do better to decline advice drawn from characteristically epidemiological studies. The faults of epidemiology are both accidental (unpreparedness for the task) and essential (unsuitability of the methods). Characteristically epidemiological methods are known to be error-prone, and when applied to bicycle transportation suffer from diversion bias, inappropriately broad-brush categorisations, a focus on undifferentiated risk rather than on danger, a bias towards unsafe behaviour, and an overly narrow perspective. To the extent that there is a role for characteristically epidemiological methods, it should be the same as anywhere
else: as a preliminary or adjunct to the scientific method, for which there is no

You may read the entire manuscript here:


A review of the film Bikes vs. Cars

I knew I’d have a problem with the film just based on the the title.

There can be animosity between people on bikes and in cars, but bikes and cars are machines, which have no feelings and generally don’t get into trouble unless there is a person is behind the steering wheel or the handlebars. The title “Bikes vs. Cars” reminds me of a frequent complaint of bicyclists who have had incidents in traffic, “the car didn’t see me.”   The title and that statement both reflect a fear-based mental block which has led to the inability to conceive of the car as a machine under control of a human, with whom it is possible to interact, and so, much more often, to avoid incidents…

Enough. There’s more to say. My facebook friend Kelley Howell has posted a detailed review, which follows here:


Why I think the film, Bikes Vs. Cars, is a waste of money:

by Kelley Howell

It was a scattered, gawky film filled with untenable contradictions. Some thoughts:

The film switched back and forth between a desire to own the streets and use them as if they belonged to bicyclists who have a right to drive on them, free of cars, but then it dropped its pretense to militancy asking for small slivers of space on the edge, as if if that edge were some Magic Kingdom of safety. On one hand, the people in the film seem to be demanding a right to take the entire road and get the hated cars off it. On the other hand, it’s all about scampering out of the way, deferring to a dominant majority no one knows how to handle, let alone challenge.

As an example, there was a line in the film which went something like this: “At 1 AM, during the quiet of Carmeggedon in LA. I sneaked on to the 405 and rode my bike on this massive highway. It was beautiful. I owned that feat of human engineering. For the first time, I felt it was a marvel of human engineering that was made for me.”

Then they switch to Sao Paulo in Brazil, to capture the happy reactions of bicyclists who learned that the city is laying down 100s of kilometers of too narrow bike lanes in a very congested city where few people appear to follow traffic law to begin with. I was hard pressed to imagine all these scrappy motorists would respect the painted lines of a 4 foot wide gutter bike lane.

Which is it: do you want to drive a bike on that feat of human engineering, the 405, or a 4 foot bike lane with cars passing too close, driving out into your path, and right- and left-hooking you constantly? How is that demanding your rights? How is it safe? Accepting a scrap of asphalt, some of it carved out of a gutter built for sewer water? After all that rhetoric of wanting access to feats of human engineering, how is that you want to operate in a gutter bike lane?

The film trades in the imagery of the bicyclist, rolling free, free of motorists, free of the burden of a body on pavement, free because it can dodge the confines of hated “traffic”. The magic of the bicycle is its thrift, its speed, and its nimble ability to slip through crevices of urban congestion. It is at once traffic and the supposed escape from it.

But this is reminiscent of the propaganda that dominates the most pedestrian – har! – of auto advertisements where cars mean freedom, an open road, an endless horizon. This imagery in commercials is a stark counterpoint to the reality of miles of congested freeway, gridlock, and, well, to borrow a phrase, the hell that is other motorists at rush hour.

This trope — the bicycle as freedom, magically evading being captured in traffic — is present in an amusing fantasy entertained in the film: pulling 20% of all motorists off the Los Angeles roads and reinserting them with their derrieres planted in bike saddles. Apparently they will accomplish their 14.7 mile commute on their Dutchie or Cruiser, pedaling along at 10 mph?

Going by LA county numbers, 20% of the ~4.5 million motoring commuters is 900,000 bicyclists. Even if their commute where far shorter – say a manageable 5 miles at 10 mph — that’s a lot of bicyclists who get to share those four foot wide gutter bike lanes. Good luck with that!

Then, there was a main protagonist, name escapes, in Brazil. She says, to paraphrase, “What I want is some respect for human cooperation.” And then the film plugs away about the lack of bike lanes. Having apparently conceded that motorists will NOT actually give bicyclists that respect or cooperatively share the roads, they ask for a sliver of space in the gutter.

Which is fine. Really. If that’s what you want. But don’t imagine segregating modes is about cooperating. It’s rather about demanding public resources be spent on gutter-based infrastructure in Brazil precisely because motorists WILL NOT share the road. No one has actually changed the domination of motorists. In this “victory,” existing configurations of power remain the same, leaving bicyclists just as powerless as they always were, only now they are marginalia set off by 6 inch stripes of paint.

The incident with the Dutch cab driver was high camp and deserves its own post. It was my impression that the cabbie staged the whole thing, a real drama queen pining for his 5 minutes on camera. Basically, it was exemplary of what Nietzsche called a transvaluation of values[1]: an opportunity for bicyclists everywhere to make the motorist suffer for a change[2].

The problem is that this is an exercise in punishing schadenfreude. We are all supposed to love it that the roles have reversed in the Netherlands. The taxi driver has to be troubled, delayed, and dominated by the majority, bicyclists. We get to engage in gleeful enjoyment to see him upset, angry, cowed by the throngs of bicyclists blocking his every move. There! Take That, you bad, bad motorists. How do you think it FEELS to be marginalized like we were?

This is a stupid and shameful sentiment that shouldn’t be tolerated by anyone doing bicycling advocacy. But it is, unfortunately, celebrated by too many participation advocates – including this film, which trades in cheap theatrics and, well, quite frankly, trashy propaganda. At least have the decency to be sophisticated about it if you are going to trade in such infantilizing sentiments.

[1] I am unhappy with the choice of ‘transvaluation of values’ to express what I mean here. But it’s been a longass day. Tant pis!

[2] As for the transvaluation of values thing, for more detail on the problems with this position, see Wendy Brown’s work States of Injury: Power and Freedom in Late Modernity. Here, Brown captures the problem as one where, basically, an oppressed or marginalized group rises in power and status, promoting a compulsion to repetition rather than liberation:

“Initial figurations of freedom are inevitably reactionary in the sense of emerging in reaction to perceived injuries or constraints of a regime from within its own terms. Ideals of freedom ordinarily emerge to vanquish their imagined immediate enemies, but in this move they frequently recycle and reinstate rather than transform the terms of domination that generated them. Consider exploited workers who dream of a world in which work has been abolished, blacks who imagine a world without whites, feminists who conjure a world either without men or without sex, or teenagers who fantasize a world without parents. Such images of freedom perform mirror reversals of without transforming the organization of the activity through which the suffering is produced and without addressing the subject constitution that domination effects, that is, the constitution of the social categories, “workers,” “blacks,” “women,” or “teenagers.”

It would thus appear that it is freedom’s relationship to identity-its promise to address a social injury or marking that is itself constitutive of an identity that yields the paradox in which the first imaginings of freedom are always constrained by and potentially even require the very structure of oppression that freedom emerges to oppose.”