Tag Archives: crash

Lessons of Spruce Street

I’m posting this in connection with the video I shot of a ride on Spruce Street, Philadelphia, Pennsylvania, already embedded in an earlier post. Spruce Street is a one-way street with parallel parking on the left side, and a bike lane on the right side except for a couple blocks where there is parallel parking on the right side also. Here’s the video. You may click on it to enlarge it. It is a high-definition video, best viewed full-screen.

Now, I’ve quite often been accused at times of being a militant vehicular cyclist.

Militant vehicular cyclists are stereotyped as disparaging all bike lanes, always preferring mixing with motor traffic.

In fact, in my ride on Spruce Street, I was being pragmatic: using the bike lane when it worked for me, leaving the bike lane when the general travel lane worked better. The bike lane worked quite well for me when I chose to use it. It safely allowed faster motorists to overtake me, and me to overtake slower motorists, between intersections.

But now, a Philadelphia cyclist, K.K. (I’ll just use initials) has turned the vehicular cycling complaint on its head, accusing me of being subservient to motorists, because I did not always stay in the bike lane on Spruce Street in Philadelphia. I’m going to try to probe the rationale for this.

What would explain K.K.’s complaint? She doesn’t say. I can only speculate. So, I’ll do that.

I spent a bit more time waiting than if I’d always ridden up to the intersection in the bike lane, but I don’t think that is the point. Assertiveness, for K.K., amounts to territoriality, as in: “the bike lane is my part of the street, and by not using it 100% of the time to get ahead, you are failing to stand up for cyclists’ rights.”

It also appears to me that K.K. thinks that militant use of the bike lane sends a message that will lead to improvements in motorists’ behavior so they respect bicyclists more, and safety will improve — the “safety in numbers” argument. Perhaps. But don’t count on it to save your life.

And it also appears that she thinks it is actually safer to stay in the bike lane, which is a sad situation, because people are getting killed by riding in the bike lane up to the coffin corner before intersections. Large trucks have been turning right from the next lane, knocking bicyclists down and running over them.

Topping off the irony, the remedy to the coffin-corner crashes now being proposed by the Philadelphia Bicycle Coalition is to force bicyclists into the coffin corner by placing a barrier between the bike lane and the general travel lane, creating what is ironically called a “protected bike lane.”

If you would like to see the specifics of K.K.’s complaint, and my responses, they are here. Yes, I know that a logical dialog doesn’t work with people whose minds are closed. But it may be useful for others to get a taste of how such minds work.

RRFBs: Time for Co-opetition

The US Federal Highway Administration has withdrawn its interim approval of  Rectangular Rapid Flashing Beacons (RRFBs) because a company which makes them has patented them. This is a serious public-policy error. The RRFB has proved effective at increasing compliance of drivers to yield to pedestrians at crosswalks.  This is most important at mid-block crosswalks and at the entrances and exits to roundabouts, where no other traffic signal is likely to be present, and the RRFB can be actuated only when a pedestrian is about to cross, minimizing delay.

While it might be possible to patent some refinement to the RRFB, the basic concept is as old as the Belt Beacon, flashing traffic signal, or railroad-crossing beacon. Patenting requires that a device be novel, useful and non-obvious, and I can’t imagine that it would be hard to get around RRFB patents, or invalidate them. But does anyone have the resources to fight these patents? And if that succeeds, it’s a Pyrrhic victory, as it also opens up the market to other competitors. Is the market for RRFBs large enough to get a company to pony up the money for a challenge, in the light of this situation? The patent and FHWA policy have killed the market too, at least in the USA, and where does that leave everyone, not least of all the patent holders? The process is broken.

What can we do to help fix this? An inventor or licensee deserves to profit from the invention, but not only does the FHWA policy prohibit use of this particular device, it also kills innovation generally. Patents are good for 20 years. Is it really acceptable for signals technology to be 20 years behind innovation, which also is stymied by lack of a market?

There has to be a better way, which rewards innovation while preventing one company from cornering the market. I’d be for some form of mandatory cross-licensing of products which are required by statute or regulation. Cross-licensing has worked in industry: prime example: in the 1950s, Ampex developed the quadraplex videotape recorder, and RCA held the patents on color TV technology. Ampex and RCA engaged in “co-opetition”, cross-licensing these technologies, and both were able to market color videotape recorders. This is what is called in highly technical language a “win-win”.But changing the rules probably requires Congressional action.

While we’re at it: a demonstration of co-opetition: the oldest known surviving color videotape recording: President Eisenhower speaks at the dedication of NBC’s new studio in Washington, D.C., May 22, 1958. The show goes into color at 14:50 and the President speaks at 16:30.

Spruce Street, Philadelphia

Bicyclist Emily Fredericks was killed, crushed by a right-turning garbage truck, on Spruce Street in Philadelphia on November 29. Another bicyclist, Becca Refford, was similarly right hooked a block away on Pine Street on December 8 and suffered serious injuries. I happened to have video of a ride I took on Spruce Street, including the crash location. I put editing of this video onto the fast track, adding narration about how to ride safely on this street, in the interest of preventing future such tragic and avoidable crashes. Please share with friends in Philadelphia.

This is high-definition video and is best viewed in YouTube at 1080-line resolution, or the highest resolution your monitor will support, if less than that. Click on the video to bring up the link to the version on YouTube.

Dutch Strict Liability Myth

A commenter on Facebook made a statement which is often heard in the USA:

“A Dutch lady said they have so few hurt because drivers are guilty unless they can prove they weren’t.”

Well, this doesn’t quite amount to fake news as such. I don’t expect that there was any intention to deceive, but it is hearsay.

The actual situation with liability in the Netherlands is more complicated, as described in the flow chart below, from a Bicycle Dutch blog post — which cites the Dutch traffic law, in case you would like to take your exploration of the topic further. You may click on the image to enlarge it.

Dutch strict liability flow chart

Dutch strict liability flow chart

I’m simplifying somewhat, but Dutch strict liability works much like no-fault auto insurance in the USA, and applies only to compensation for injuries, not to penalties.

An undertaking undertaking

I answered this question on the Quora question-answering site.

Who is at fault if a driver undertakes you from behind you while you are safely making a left turn on a one-way road?

First, let’ define “undertaking”. That doesn’t mean that the vehicle is a hearse. It means that the vehicle passes between yours and the edge of the road when you are near the edge and turning toward it. Since the question mentions a left turn, the questioner is probably in a country where traffic keeps left by default and normally passes on the right. The term ‘undertake” is more commonly used in the British Isles than in North America in any case. But the question could apply to a left turn from the left side of a one-way street anywhere.

Usually, the driver who undertakes is at fault. Generally there is not room for another dual-track vehicle to pass between the turning vehicle and the edge of the roadway, though there may be room if more than one lane allows left turns, or room for a single-track vehicle (motorcycle, motorized bicycle, bicycle). A driver might also undertake on a highway shoulder or by driving off the road. In any of these cases, it is illegal.

Some countries place a bicycle lane or barrier-separated bikeway in the path of the turning traffic, and if the undertaking driver is a bicyclist, the turning driver is held at fault. The resulting conflict may be not mitigated at all, or mitigated in any of several ways — with warning signs, street geometry, street markings or traffic signals. The intention of this arrangement is to relieve bicyclists of the burden of mixing with motor traffic to travel straight through the intersection, and so, placing all of the responsibility for avoiding collisions on the motorist.

Because of the speed with which bicyclists travel, the turning driver is required to look to the rear to the side toward which he or she is turning, rather than only first merging to the lane position for the turn and then yielding to pedestrians who are standing on the corner or walking in the crosswalk. Looking to the rear imposes an additional task burden on the driver at a time where attention to the front and sides is also in demand, and may even be impossible, depending on the geometry of the intersection and the design of the turning vehicle. Unless drivers know to expect this conflict and mitigating factors are in place, this is a risky situation, often resulting in what is called in the USA a “right hook” collision. It also reduces the throughput of intersections by requiring additional waiting — sometimes by motorists, sometimes by bicyclists and sometimes by both.



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.

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.

About the bicycle radar reflector Kickstarter campaign

This article has been translated into Portuguese. Brazilian flag
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 characteristics 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.










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.

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.