Tag Archives: bicycle

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.

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.

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.

Children’s abilities — focusing on peripheral vision

My previous post addressed children’s cycling abilities. I’d like to take the discussion a bit further here.

A conventional statement about children’s cycling abilities, as expressed on an e-mail list, is:

Children also have less than fully developed peripheral vision and are very poor judges of the speed of automobiles.

Pioneering cycling educator John Forester replied:

Presumably, it depends on the age of the child. Many of us have known children aged seven, who have grown up in cycling families, who cycle in accordance with the rules of the road for drivers of vehicles. The ability is there; it just has to be trained. I have taught classes of eight-year-olds who learned to cycle properly in the traffic of two-lane streets in residential areas. I fail to see much point in the peripheral vision worry, because all cyclists have to learn to look at whatever is going to be important; what’s out at the side has little relevance. As for judging the speed and distance (you need to know both) of other traffic, say automobiles, any person has to learn to judge whether or not there is time to make a movement or it will be necessary to wait. I’ve watched the judging skills of eight-year-olds improve as they practice various traffic movements. In my opinion, the people who express the concerns about such mental matters have not had experience in training cyclists; they just measure (or try to measure, or make assumptions based on irrelevant measurements, or …) children without any knowledge of what is actually required for cycling in traffic, and are therefore completely ignorant of how to learn the skills.

I wouldn’t have been as harsh as Forester, but I agree that reliance on data from research into mental or perceptual abilities, without actually measuring cycling performance, misses the mark. Abilities do appear sequentially, as shown for example in this paper. There are studies which show that the acquisition of skills in childhood can be advanced by a couple of years through training. The minimum age to obtain a driver’s license reflects a societal judgment of the maturity necessary to drive safely.

I think, however, that the claim that children of elementary-school age have limited peripheral vision is commonly misstated and misinterpreted. It isn’t that the range of angles of peripheral vision increases — as if a child’s retinas have only a small patch of sensory receptors at the center — “tunnel vision” — which expands over the years. I say this from my own experience.

What is importantly less developed in children is the conscious awareness of the peripheral visual field. It sends too much and too complicated information for the immature or untrained brain to process fully.

I recall a peripheral-vision experiment at school when I was 8 or 9 years old, checking how far to the side I could place my hand before I could no longer perceive the wiggling of my fingers. The angle was the same approximately 90 degrees as it still is 60 years later — except that I could perceive the wiggle but not yet the shape of the hand. From age 3, I rode a tricycle, from age 7, I rode a bicycle and from age 17 I drove a car, and did not fail to notice hazards in the peripheral visual field. Peripheral vision short of full, conscious perception, and like the spatial sense of hearing, serves to draw attention, so the eyes and head turn to focus central vision.

I learned to perceive my peripheral visual field consciously in my twenties. I trained myself by focusing my attention on objects in the peripheral field instead of turning my eyes to look at them. This can look weird in social situations! I undertook most of my training while riding my bicycle. Over a period of a couple of years, I got to where I am as conscious of my peripheral field as my central field, except that the peripheral field is blurrier. I see the entire panorama in front of me at once.

Moreover, the rod cells, sensitive enough even to form an image under starlight, are only in the peripheral visual field. The fovea, at the center of the visual field, has only the color-discerning and sharp-imaging cone cells, which are far less sensitive,. In very dim light, the center of the visual field becomes a blind spot and, to fill it in, the eyes must dart around like those of a person born without cone cells — as described in Dr. Oliver Sacks’s book The Island of the Colorblind. Walking outdoors on a starlit night in an area with dark sky offers a good lesson about visual abilities.

Is the NACTO Guide a Design Manual?

In cities around the USA, politicians, under pressure from populist bicycling advocates, have pointed to the NACTO (National Association of City Transportation Officials) Urban Street Design Guide and directed their engineering staff to install treatments which it describes.

I’ll say right here that some of the treatments which the NACTO guide describes deserve attention and inclusion in national design standards — though their presentation in the NACTO Guide typically is flawed, inconsistent and incomplete. Why some deserving treatments are not included in the national design standards is a story for another time.

Other NACTO treatments are so troublesome that they are not widely applicable.

Engineers unfamiliar with bicycling issues may take NACTO designs at face value; other engineers may throw up their hands and comply, faced with the threat of losing their employment. Several engineers who have extensive background and expertise in design for bicycling have resigned, been fired or been demoted when they would not accept the NACTO designs.

What leads to these problems? To put it simply, the NACTO guide isn’t a design manual. It is a smorgasbord of design treatments formatted — right down to digitally-generated loose-leaf binder holes on what are, after all, Web pages — to look like a design manual to politicians and the general public. Bicycle manufacturers funded it to promote street designs which they expect will lead to greater bicycle sales. It lacks the vetting necessary for consistency and accuracy. Its purpose is to generate political pressure to apply the treatments it describes. It is weak on specifics: rife with errors, and with omissions even in describing the treatments it covers.

If I described all of my specific  concerns with the NACTO Guide, I’d be writing a book, so for now let’s just look at a two-page spread of the NACTO Guide, the pages about two-stage turn queuing boxes (2STQBs, for short).

Maybe by now you are inclined to think of me  as a naysayer, so, let me get down to some specifics to dispel that impression. I have had information about two-stage turn queuing boxes online for years, I think that they are a useful treatment, and I use two-stage turns: when I realize that I have reached the street where I need to turn left, but hadn’t merged to turn; when traffic is heavy and fast and I haven’t found an opportunity to merge; when ordinary left turns are prohibited. My favorite example is the left turn from Commonwealth Avenue onto the Boston University Bridge in Boston, Massachusetts, where a no-left-turn sign is posted: motorists have to go around a large loop.

Ok, now let’s consider the spread from the NACTO guide, below.

NACTO pages about two-stage turn box

NACTO pages about two-stage turn queuing box

I have placed that spread online as a PDF file, zoomable to any size you might like. You may click on the link or the image above to get a larger view while reading this text. The PDF will open in a separate browser window or tab. I’ve also posted parts of the NACTO pages in connection with the text below.

Issues of organization and use of technical language

The NACTO treatment of the two-stage turn queuing box presents issues of organization and of use of technical language.

Problems start with the title of the section. A proper title is not “Design Guidance”, otherwise, every section would be named “Design Guidance”. A proper title is the name of the device, here “Two-Stage Turn Queuing Box”. [And not "Queue" but" Queuing."]

In a proper design manual, the terms “shall”, “should”, “guidance” and “option” go from strong to weak. “Shall” is imperative: for example, a stop sign shall be octagonal. Should, guidance and option statements are increasingly weaker, leaving more room for engineering judgment.

The terms “Required Features” and “Recommended Features” correspond roughly to “shall and “should” but do not have the explicit, legally-defined meanings of “shall” and “should”.

None of the drawings on the two pages are dimensioned, and no dimensions are given in the text. That is to say, these are not engineering drawings, they are only conceptual drawings. How big are the turn boxes supposed to be? Who knows? The width of travel lanes differs from one drawing to the next, but no explanation is given for that. When politicians start beating on the door for NACTO treatments, standards-setting bodies and traffic engineers have to try to fill in the missing information. For specific projects, that task often is passed along to hired consultants who make their living by promoting and designing special bicycle facilities. Yes, there is a conflict of interest.

Specific comments

Now, either click on the image of each section of the page below to open it in a separate browser tab, or zoom the PDF to at least 50% size so you can read the text in connection with my specific comments .(You may open it now if you didn’t already.)

Comments on the left-hand page

The left-hand page includes text which may look like design specifications, and drawings which may look like design drawings — to a layperson.

Left half of left-hand page


Point 1: “An area shall be designated to hold queuing bicyclists and formalize two-stage turn maneuvers.” This is under the heading “Required Features.”  A 2STQB is only one way to turn left among others, an option, subject to engineering judgment or specific design warrants. There is neither the room nor the need for a 2STQB at most intersections. Lacking here is any statement as to where a 2STQB is appropriate, but the “shall” statement here is inappropriate: appropriate shall statements would describe what features are required if a 2STQB is installed. As of May 2014, the 2STQB is still in experimental status with the Federal Highway Administration — as are all details of its design, and so no “shall” statement at all is appropriate.

A proper design manual would include guidance about speed and volume of traffic; the additional delay usually required for a two-stage turn; whether bicyclists might take an alternate route entirely; whether use of the box is  mandatory, placing bicyclists who make other types of turns in violation of the law.

Point 4: “In cities that permit right turns on red, a no-turn-on-red sign shall be installed.”

According to the wording here, if the installation is not in a city, the sign is not required.

But also, the shall statement is overly broad, and incomplete. The sign is needed only if right-turning traffic would be in conflict with the bicyclists waiting in the 2STQB: unnecessary in the cross street if traffic turns right before reaching the box or cannot turn right, and unnecessary on the entry street if the cross street is one-way right-to-left. Does the sign belong on the entry street or the cross street, or both? That is not stated. Details, details…

Point 6: The comma makes nonsense of this sentence. Where is the box to be positioned?

The other, subsidiary “should” and “may” statements on this page also are contingent on official approval of the underlying design, and are lacking in detail.

Right half of left-hand page


Something really leaps out at me here: take a look and see whether it leaps out at you too.

OK, ready? Three of the six illustrations show a line of travel (in blue) for bicyclists straight across an intersection and then illegally and hazardously turning right, directly into the face of approaching traffic in a cross street.

In showing this bizarre routing, the NACTO Guide also fails to address issues with the actual route which bicyclists might take.

Five of the six illustrations show that bicyclists would somehow turn 180 degrees in place. That requires dismounting and is slow and awkward. How would a bicyclist turn when the traffic light is about to change? When other bicyclists are already in the box? What about tandems? Bicycles pulling trailers? Bicycles carrying heavy baggage?

The drawings show a subtly implied but selectively addressed-threat: lanes where motorists travel are shown in a threatening shade of pink — whoops: except in the cross street where bicyclists ride head-on at motorists.

Four of the six illustrations show motor vehicles in right-hook conflict with bicyclists headed for the queuing box. The motor vehicles are turning out of the threatening pink area into what is portrayed as the safe zone– the right-hook zone. In two of the pictures,  vehicles have already impinged on the blue line which represents the path of bicyclists crossing the intersection. Green paint, which has become a catch-all warning of traffic conflicts in bicycle facilities, is shown in the queuing box, it is not shown in the conflict zone. (By way of comparison, Dutch practice in such conflict situations is that the motorist must always yield, and to use “shark teeth” markings to indicate a yield line.)

Two of the drawings show bike lanes in the door zone of parked cars.

The middle left illustration shows a receiving bike lane at the top, out of line with dashed markings in the intersection, so bicyclists bear right just before they cross a crosswalk, potentially colliding with pedestrians who would expect them to continue straight.

All of the illustrations show two-stage turns across two-lane one-way streets, though the two-stage turn queuing box is most useful where a conventional left turn is illegal, unusually difficult or hazardous — for example, when turning from a major, wide arterial street with heavy traffic, or one with trolley tracks in the median.

As already indicated, none of the drawings are dimensioned and no dimensions are given in the text.

Comments on the right-hand page

The right-hand page gives annotated pictures of conceptual installations, with angled views from overhead.

Left half of right-hand page


The street going from bottom to top in the picture is one-way, as can be inferred by the direction in which vehicles are traveling. That the cross street is two-way may be inferred from the locations of traffic signals and the existence of the queuing box. A real design manual would be explicit about how a treatment would apply, depending on the directions of traffic in the streets.

The end of the traffic island next to the queuing box protrudes so far and is so sharply as to make right turns awkward. No explanation or guidance is given on this issue.

Traffic signals are shown for motor traffic on both streets, but no traffic signal is shown facing the separate bikeway in the street!

Point 3: “Shall” — mandatory — wording differs from that in the same point as made on the opposite page. A real design manual would have a single, consistent statement. “Queue box shall be placed in a protected area.” The queuing box shown here is not protected from right-turning traffic in the cross street. How would that right-turning traffic be managed, or is it permitted at all? Such issues are addressed in a real design manual.

Point 6: “Optional queue box location in line with cross traffic.” The preferred queuing box, then, is not in line with cross traffic. On getting a green light, bicyclists in the queuing box would have to merge left inside the intersection unless there is a receiving bike lane after the intersection, but none is shown. Merging inside an intersection results in hazardous conflicts and is generally illegal. What warrants the choice of one or the other option? It isn’t stated.

Point 8: The illustration shows motorists and a bicyclist inside the intersection, and so they must have a concurrent green light — or, they would if any signal were shown facing the bikeway. Markings guide bicyclists across the intersection, but also into the path of right-turning traffic. The bicyclist and the motorist in the right-hand lane at the bottom of the picture are on a collision course if the motorist turns right.

What is the meaning of the curved markings adjacent to the bicycle parking in the middle of the street? Does the lane with bicycle parking start as a lane with car parking, additionally hiding bicyclists from turning motorists? Or is this an additional lane for motor traffic, discontinued at the intersection, precisely where more lanes are needed to store waiting traffic? Not shown.

Right half of right-hand page


There is a right-hook threat at both bike lane entries to the intersection.

Bicyclists headed from bottom to top in the bike lane are riding in the door zone of parked cars, and closer to the cars after crossing the intersection.

Point 9: As in the left half of the page, placing the queuing box to the right of the travel lane when there is no receiving lane ahead assures that motorists will overtake bicyclists in the intersection and that bicyclists will have to wait for motor traffic to clear before they can proceed. Motorists waiting to turn right will be stuck behind the bicyclists. Placement out of line with motor traffic is described as the option here, rather than as the preferred treatment as on the left side of the page, and the problem is acknowledged in the caption to this drawing, though no explanation for the different choices is given.

Point 10: A jughandle may be useful if traffic is so heavy or fast that bicyclists have difficulty merging to the normal left-turn position near the center of the street, but then traffic is also so heavy and fast that a signal is usually necessary, not merely to be considered — unless there is already one upstream.

Point 11: Yes, signage may be used, but what signage? A real design manual would show the signs and where they are to be placed.

Point 12: A bicycle signal might be installed, but where? for the entry? For the exit? Its timing?

Point 13: Guide lines, pavement symbols and/or colored pavement. Which? Where? Why?

Had enough?

Sloppy cycling meets sloppy journalism

Washington, DC TV station WJLA, channel 7, has run a story about new bicycle laws passed by the DC City Council and signed by the mayor. The new section reads as follows:

A new section 9d (D.C. Official Code § 50-2201 .04d) is added to read as follows:

“Sec. 9d. Bicyclists’ use of leading pedestrian in tervals.
“(a) A bicyclist may cross at an inter section while following the pedestrian traffic control signal for the bicyclist’s direction of travel unless otherwise directed by traffic signs or traffic
control devices.
“(b) A bicyclist may cross an intersection where a leading pedestrian interval is used.”

Questions have been raised by cyclists in an online group I belong to, for example, “So how are the bicyclists supposed to reach the intersection when no bikeways are present? By lane splitting? Filtering forward on the right? Using the sidewalk? Or are bike lanes and boxes supposed to be provided at all intersections? This will be a boon to red light runners and further the bad mixing of bicyclists and peds as “one category”, or as some like to say, further the pedestrianization of bicycling.”

But I’d like to discuss the video itself. It came with an embed code, and here it is.

After 15 seconds of an ad for an Infiniti SUV, you’ll get to see the news story about bicycling.

Much of the narration in the video is posted on a Web page under the headline

D.C. cycling made safer with new rules of the road

That headline is rather interesting not only because of the questions which have been raised, but also because the law isn’t even in effect yet. In a year or two we might have data as to whether cycling has become safer. It would be much more difficult to determine whether that resulted from the new law. A recent study did show that cycling is becoming less safe the crash rate is increasing in Washington, DC — as might be expected when large numbers of new and inexperienced cyclists enter the traffic mix.

The text identifies interviewees — though only by their last names. One is named Clarke. More about that later. Also there are bike-cam shots in which you can see the cyclist’s plaid sleeves. This leads to an interesting discovery. My rundown of the video:

0:00 The words “outrage” and “alarm” are used. Inset on the screen reads “Bike vs. Car.” The TV station is pandering to motorists’ sense of entitlement and identifying inanimate machines as doing battle with each other, as a surrogate for operators of those machines placing them in conflict with each other. The concept of cooperative use of the public streets gets short shrift in this video.

0:49 Bicyclist in the plaid shirt threads the needle between a stopped SUV and a bus, placing him immediately directly in front of the bus. Nice thing the bus wasn’t about to start up. Headache for the bus driver in any case.

0:52 another cyclist waddles out from behind a stopped vehicle in front of another vehicle which is just starting to move.

1:02 the man on the street being interviewed is wearing the same plaid shirt as the one in the on-bike video making dumb moves. In the online text his name is given as “cyclist Billing” and he uses the royal “we.” “We” is WABA: Greg Billing writes blog posts for WABA and has written one about this new law.

1:05 Billing is shown turning left and heading for a door-zone bike lane to filter forward. Shot is cut off abruptly before he reaches the lane.

1:12 Cyclist identified in the text as Senff justifies advanced green on ped signal so “you don’t feel so, I don’t know…pushed.” How that applies when starting ahead of the motor traffic, I don’t know.

1:25 Through-the-windshield shot as car enters a combined bike lane/left turn lane, which figures later in the video too.

1:35 Truth is spoken by a man identified as Bradford: not all bicyclists operate properly.

1:40 Narration is about a bicyclist operating responsibly, but the bicyclist shown in one of many low-angle mood shots has a shopping bag dangling next to the front wheel.

1:45 The narrator complains of a bicyclist overtaking a motorist who is signaling a turn. The bicyclist, seen through a car windshield, is legally in a combined bike lane/left turn lane to the left of a through lane from which a motorist ahead is preparing to turn left illegally. Flex posts would keep a knowledgeable bicyclist from merging out of the bike lane. The driver preparing to turn left couldn’t make sense of the intersection design, and the bicyclist was blissfully unaware of the risk. The layout here is the same as at 1:25 in the video — it might even be the same intersection — and similar to the one at Market and Octavia Streets in San Francisco where fatal crashes have occurred.

1:50 The unidentified Clarke is revealed to be an African-American woman, not Andy Clarke, President of the League of American Bicyclists.

1:54 Billing provides a bike-cam shot, riding at speed in a left-turn lane going too fast to turn left, but the shot is cut just before he reaches the intersection.

2:15 A cyclist is in the door zone and uncomfortably close to a pedestrian.

2:20 — The law has to be voted on by Congress. It isn’t yet in effect.

All in all, there’s plenty enough cluelessness to go around, with this video, but I do agree with Mr. Bradford!

Truck side skirts: reliable way to prevent cyclist fatalities?

No, not reliable. And they are also supposed to confer an aerodynamic advantage. Some do, some don’t.

Some have a smooth surface which can deflect a cyclist. That is still no guarantee that the cyclist will escape serious injury or death. Other side guards are only open frameworks which can catch and drag a bicycle. A lot of what I have seen is little more than window dressing.

The side guard in the image below from a post on the Treehugger blog has no aerodynamic advantage and could easily guide a cyclist into the rear wheel of the truck.

Photo of truck side with guard from Treehugger blog.

Photo of truck side with guard from Treehugger blog.

A cyclist can easily go under the side guard shown in the image below, from a Portland, Oregon blog post. A cyclist who is leaning against the side guard is guided into the sharp edge of the fender bracket and fender, and the front of the turning wheel, which can pull the cyclist down. There is another wheel behind the one in the photo.

Side guard on City of Portland, Oregon water transport truck

Side guard on City of Portland, Oregon water transport truck

The side guard on a Boston garbage truck in the photo below — my own screen shot from the 2013 Boston Bikes annual update presentation — is only an open framework which could easily catch and drag a bicycle.

Side skirt on City of Boston garbage truck

Side skirt on City of Boston garbage truck

A truck which is turning right off-tracks to the right. A cyclist can be pushed onto his/her right side, and goes under, feet to the left, head to the right. On the other hand, if an overtaking truck contacts the left handlebar end, or if the right handlebar end contacts a slower or stopped vehicle or other obstruction, the handlebar turns to the right and the cyclist slumps to the left, headfirst.

To be as effective as possible for either aerodynamics or injury prevention, side guards must cover the wheels. Though that is practical, none of the ones shown do.

But no practical side guard can go low enough to prevent a cyclist from going underneath. The side guard would drag  at raised railroad crossings, driveway aprons, speed tables etc. Even if the side guard did go low enough, it would sweep the fallen cyclist across the road surface, possibly to be crushed against a parked car or a curb.

Fatalities have occurred when cyclists went under buses, which have low side panels — but the wheels are uncovered. The Dana Laird fatality in Cambridge, Massachusetts is one example. Ms. Laird’s right handlebar end is reported to have struck the opening door of a parked vehicle, steering her front wheel to the right and toppling her to the left.

Dana Laird fatality, Cambridge, Massacchusetts, 2002

Dana Laird fatality, Cambridge, Massachusetts, 2002

The bicycling advocacy community, as shown in the blog posts I’ve cited, mostly offers praise and promotion of sub-optimal versions of side guards, a measure which, even if executed as well as possible, offers only a weak, last-resort solution to the problem of bus and truck underruns.

Most of the comments I see on the blogs I linked to consider it perfectly normal for motor traffic to turn right from the left side of cyclists, and to design infrastructure — bike lanes in particular — to formalize this conflict. The commenters also would like to give cyclists carte blanche to overtake close to the right side of large trucks, and place all the responsibility on truck drivers to avoid off-tracking over the cyclists.

Cyclists are vulnerable road users, but vulnerability is not the same as defenselessness. It is rarely heard from today’s crop of bicycling advocates, but a cyclist can prevent collisions with trucks and buses by not riding close to the side of them. There’s a wild contradiction in playing on the vulnerability, naiveté and defenselessness of novice cyclists to promote bicycle use with measures — particularly, bike lanes striped up to intersections — which lure cyclists into a deathtrap. Regardless of whoever may be held legally at fault in underrun collisions, cyclists have the ability to prevent them, and preventing them is the first order of business.

Want to learn how to defend yourself against going under a truck? Detailed advice on avoiding bicycle/truck conflicts may be found on the Commute Orlando Web site.

Additional comments about the political situation which promotes underrun collisions may also be found on that site.

Support for the Allies in WWII, wrapped around a bicycle sprocket

I wrote to Sturmey-Archer’s European office a few months ago concerning the Swiss-made Vibo three-speed hub described on the Sturmey-Archer Heritage Web site. The Web page about this hub indicates that a scrap of paper which enclosed the sprocket in the shipping box shows German troops marching into Paris. It doesn’t. The page hasn’t been corrected, so I’ll make a correction here.

Here’s the scrap of paper. You can click on the image to enlarge it, and read the caption if you happen to read French.

The scrap of paper which wrapped the Vibo hub

The scrap of paper which wrapped the Vibo hub

Here’s translation from the French on the scrap of paper.

Underground mobilization
in the Paris sewers and catacombs

(continued from no. 29)

A city full of passion and hope

Since the start of the invasion, German illustrated newspapers have ostentatiously been publishing images of Paris which the propaganda agencies accompany with strange commentaries. Here is an example: it is supposed to prove that Paris is hostile to the Anglo-Saxon invaders and that it openly supports the acts and cause of its oppressors. While the tank battle rages in Normandy, German power is being asserted in the French capital through the organization of large demonstrations by reserve troops along the avenues and boulevards. The Germans do not seem to be troubled by the developments alongside and below them, appearing to be content to drown out the muffled rumblings of the partisan army in the underground city with the sound of boots on the Champs Elysées. The Germans are surrounded by large crowds which “applaud spontaneously, clap their hands and throw flowers.” But who, then, has checked whether these are Parisians? There are two hundred thousand German civilians in Paris, to whom might be added, as in any large city, a certain number of women of easy virtue. Let us recall 1870 and the well-known heroines of Maupassant’s stories. There is nothing mysterious about this image. The Champs-Elysées? Yes. But Paris? No!

This establishes a few things:

  • The hub was shipped no earlier than the weeks in 1944 after the D-Day invasion but before the liberation of Paris — not when “German troops were marching into Paris,” as indicated on the Sturmey-Archer Web page.
  • Therefore, any lawsuit to stop production of this apparently unauthroized copy of the Sturmey-Archer AW hub did not succeed till after that time (and I suspect, wouldn’t get much attention while the war was raging).
  • As Switzerland was neutral, the hub could have been exported to Germany or a German-dominated country — including French-speaking countries — and so the message might have been chosen intentionally as an indication of support for the Allies against Nazi Germany. Note how neatly the paper is torn to preserve the image and caption!

It is also understandable that a Swiss company would take up manufacture of a copy of a Sturmey-Archer hub during the war. There was no way to get the real thing in Switzerland, which was surrounded by Axis and Axis-dominated countries. Also, production of bicycle components — especially for export — in both Allied and Axis nations was limited by the war. The threat of a lawsuit from England would be much less of a concern than action — legal and diplomatic — by the neighboring Germans; the Swiss manufacturer and/or employees clearly were more sympathetic to the Allied cause, and might also expect customers to be. Therefore, a copy of a British hub would probably be better received than a copy of a German one, even though illegal.

Boston Globe: Reality Check Time

The caption with the picture below in the Starts and Stops column of the Metro section of the June 17, 2012 Boston Globe reads:

Cyclists stopped for a red light in the “bike box” on Commonwealth Avenue in the Back Bay. They provide the cyclist a safe space to wait ahead of cars at traffic signals.

Photo which appeared in the Boston Globe Metro section, June 9, 2012

Photo which appeared in the Boston Globe Metro section, June 9, 2012

(The Globe story may be behind a paywall, but you can probably access it through a public library’s Web site using your library card number.)

The smiling cyclists show that this is a posed photo; the photographer evidently only thought of the large puddle in the foreground as an artistic touch. How about the car encroaching into the bike box in the background?

Well, yes, OK, waiting in the bike box might be safe — drivers are unlikely to encroach on a cyclist who is already waiting in the bike box. The problem is with getting into the bike box. The Globe columnist, Eric Moskowitz, never considered that bicyclists approaching the bike box on a red light are encouraged to swerve sharply left across multiple lanes of motor vehicles, with no way to know when the light will turn green. A waiting motorist will not see the swerving cyclist if looking to the left for traffic at the wrong moment. A tall vehicle in one lane will conceal the cyclist from a driver waiting in the next lane.

Portland, Oregon has hosted a study of bike boxes, which found that this is actually a rare problem in Portland, because cyclists are smart enough not to swerve into the bike box. Instead, if the light is red, they wait at the right curb, blocking other cyclists behind them. I saw the same thing on Commonwealth Avenue. As I said before, the Globe photo is posed.

But on the green light, there’s another problem. Bike boxes and the bike lanes which lead to them invite cyclists to overtake waiting motor vehicles on the right, risking getting struck by a right-turning vehicle. A bicyclist was right-hooked and killed in Portland, Oregon, on May 16, 2012 but apparently that news didn’t reach the Globe’s columnist, or didn’t make an impression on him. Now a letter from the City of Portland is conceding that car-bike crashes have increased at some of the intersections where bike boxes were installed. So much for the Globe’s assertion of safety.

Conscientious bicycling advocates have been warning about the “right hook” problem for decades, based on the difficulty which motorists have in looking into their right rear blindspot, while also checking the intersection ahead.

Swerving across is illegal too: here’s the Massachusetts law, in Chapter 89, Section 4A. It applies to bicyclists, the same as other drivers. Every state has a similar law.

When any way has been divided into lanes, the driver of a vehicle shall so drive that the vehicle shall be entirely within a single lane, and he shall not move from the lane in which he is driving until he has first ascertained if such movement can be made with safety.

Bicycling advocates, planners and government officials who promote bike boxes have simply chosen to pretend that this traffic law doesn’t exist, or can be ignored. Same for the limits of human abilities.

Now, I wouldn’t be fair in making this criticism if I didn’t suggest alternatives.

The one I favor is for cyclists to merge before reaching the intersection. That can be facilitated by signal timing at the previous intersection to allow cyclists to merge across when motor traffic is stopped, and a clear lane into which to merge.

Other suggestions have been to prohibit right turns, or to install special signals to warn cyclists that the light is about to change. Denver’s retired bicycle coordinator, James Mackay, has described some of the measures used in European cities.

These measures will, however, result in more delay, for both cyclists and motorists.

It may be more practical just to designate another street as the one for through bicycle traffic, My favorite suggestion at this Back Bay location would be Newbury street, configured as a two-way bicycle boulevard with a bridge over the Muddy River to connect it with the Fenway area.