John S. Allen's Bicycle Blog

Cycling educator John Forester gets a lot of flak from people who reject his advocacy of cycling skills, preferring a populist, facilities-based “paint and path” approach.

Forester has brought abuse upon himself with his abrasive, confrontational style. But let’s not anybody forget that Forester was a game changer. His book Effective Cycling, first published in the 1970s, pioneered with its advice on crash avoidance maneuvering, lane positioning, preparing for turns, nighttime equipment needs — supporting this advice with a review of research literature.

Recently, Forester also has been criticized from another side, for not recommending assertive enough lane positioning. (I understand that he has revised his advice in the recent 7th edition of Effective Cycling — though I haven’t read that yet.)

Still, Forester’s advice on avoiding car-door collisions in the early editions of Effective Cycling — though a bit weak by current standards — was very different from that of other cycling authors. I’d say that Forester pushed the indicator needle about 3/4 of the way across the dial.

My comparison of advice on avoiding car-door collisions in four books from the 1970s: Forester’s, and the very popular ones from Eugene Sloane, Fred DeLong and Richard Ballantine — makes all this clear enough, I think.

I’ve read a very interesting article about the insurance and liability aspects of robocars.

This post expands on a comment I posted on the author’s blog.

I think that the question of interaction of robocars with pedestrians, bicyclists and human motorists deserves deep scrutiny. As the author describes, a robocar is cautiously going to attempt to avoid collisions — but humans break laws, play bluff and take risks. That means, for example, that a robocar will stop for a pedestrian illegally stepping off the curb, or a car inching out from a stop sign, or a bicyclist riding against traffic — while a human driver might blow the horn and expect the pedestrian to retreat, the motorist to stop, or the bicyclist to dart into a parking space. A game of give and take, — or if you prefer, “chicken” — occurs in such situations — where both participants take stock of their ability to avoid a crash if the other keeps moving, and one or the other — usually the one who is breaking the law — gives way to the other. I see the potential for robocars to bring mixed traffic to a stop, because humans will outbluff them. Where does this lead? To robocars’ being allowed only on limited-access highways, where traffic conditions are uncomplicated? To traffic in urban areas being reduced to the speed of bicyclists, because robocars are more cautious about overtaking than humans are? To banning bicyclists, pedestrians and human motorists from roads where robocars are permitted to operate robotically?

A friend posted a photo on Facebook, like this one (replacement — the Facebook one is now archived.)

The placement of the shared-lane markings shown, centered in the lane, is good. The shared-lane marking is a standard treatment in the Manual on Uniform Traffic Control Devices (MUTCD), as is green paint for use in bike lanes. As of this writing, the green paint underlay of a shared-lane marking is in experimental status. Issues which might oppose it: the expense of the added paint; does it actually affect behavior; the “cry wolf” effect of use of green paint in increasing numbers of types of installations.

Traffic control devices — signs, signals and markings — are supposed to express a consistent symbolic language. In North America and in countries influenced by North American practice:

• Rectangular signs with a white background are regulatory signs — that is, they indicate what the law requires. Examples are speed limit signs, no-parking signs, no turn on red signs.
  
• Yellow, diamond-shaped signs are warning signs, indicating a potential hazard or the need for caution.
• Green signs with white text are directional signs, or wayfinding signs. Examples are street-name signs, the signs preceding off-ramps on interstate highways and bike route signs.
  
• And so on — blue background: emergency routes or services; brown background: parkland information; orange: construction zones.
• Similarly for paint on the road, yellow is for a line or area which drivers are not supposed to cross; blue, for handicap parking; green, for use in bike lane conflict zones; white, for most other road markings.

Of all of the colors for road paint, green, being the newest, is the one least standardized, and there is a tendency to use it indiscriminately, — so road language becomes road slang, with inconsistent and changing meanings.

The experimental process leading to inclusion of new signs, symbols and markings in the MUTCD is intended to refine, and define, their use, and to forestall the confusion which results from indiscriminate use.

This process has sometimes been criticized for being too cumbersome, but on the other hand, consistency matters!

The German Cycling Federation (ADFC) has posted a page describing changes which remove some restrictions on cyclists [http://www.adfc.de/9641_1, no longer available and not archived]. I have prepared a translation of the page.

Please keep in mind that translations do not necessarily reflect my own opinions.

I also have posted translations of other documents about German traffic law and cycling conditions.

The Berlin Police Department study, 1987, with my comments (shows hazards of sidepaths).

ADFC report on a conference in Vienna, 1990

Press release by an ADFC section about sidepath hazards

Bernd Sluka’s survey of German traffic law concerning sidepaths

Bernd Sluka’s survey of sidepath safety

ADFC page about contraflow bicycle travel

A more detailed discussion of contraflow bicycle travel from the ADFC, and my comments

A synopsis of research on contraflow bicycle travel

The ADFC on shared bus-bike lanes

A more detailed discussion on bus-bike lanes from the ADFC, and my comments.

I’m commenting here on an article in the Washington, DC City Paper blog,

“There is No War on Cars.”

Excerpt:

“Except that there was a car war. It was just in reverse: Cars were declaring war on cities across the country.”

And a commenter on an e-mail list adds:

I’d add “and people” after “cities”.

Cars are machines and cannot declare war. Mischaracterizing the degradation of street use as a war makes it harder to understand. It is a tragedy of the commons — misuse and degradation of a resource held in common, where individuals reap the benefits but society at large is burdened with the costs. Sometimes the very residents who once walked the street now drive and park cars in it — but also outsiders do, as cars are mobile. On local streets, this typically occurs slowly, by degrees. The classic cartoon by R. Crumb describes the situation well enough. (Click to open and click again to enlarge).

Hmm, not the first time I’ve said something like this.

The transition occurred in US cities in the early and mid 20th century, but I’ve witnessed a more recent example: over the years, where I go on vacation, more and more people have built cottages farther away around the lake. These people are more hurried, and they and have little investment in the safety of children crossing the street in the middle of town to get to the lakefront. War? The change is hardly noticeable from one year to the next, but it is dramatic now compared with 60 years ago.

On the other hand, political battles — between people — do occur over destruction of neighborhoods to construct highways or widen streets, and over reclaiming streets.

I often see similar anthropomorphizing of machines in descriptions of traffic incidents e.g., “the car didn’t see me”. That wording may become more appropriate with self-driving cars but Heaven help us if cars are programmed also to be able to declare war!

A California bicycle shop posted the photo below of a tandem made by Specialized S-Works — the part of the company which produces high-end, innovative bicycles.

This is a show bicycle and concept bicycle, “must be better because it’s got a carbon-fiber frame and has (wow), shaft drive.” However, drive from the rear crankset to the rear wheel reverts to chain drive, which allows of multiple drive ratios.

A reader where the photo was posted on Facebook remarked that “formula one racing motorcycles all use a chain drive. With that shaft drive the power has to change 90° twice. Minimum 5% power loss compared to chain drive.” As only the power from the captain (front rider) passes along the shaft, power loss on this tandem might be somewhat less.

The frame has to be heavier to resist the torque produced by the shaft. A tubular shaft could probably be as light as a chain.

With no seat tubes, the frame may provide a greater suspension effect, but at the cost of greater weight due to lack of triangulation. In a tandem, there is a major requirement for torsional stiffness around a longitudinal (front-to-rear) axis, and computer analysis may have shown that the structure necessary to achieve this also optimizes strength and vertical stiffness/suspension without seat tubes.

The saddles and seatposts are integrated and non-adjustable. Saddle height can be changed only by replacing a saddle. Handlebars can be adjusted only by replacing the entire front end assembly. This bicycle, then, is effectively limited to use by the same pair or riders. If not for the inefficiency of the shaft drive, I’d say that it might be suitable for pro racers, for whom cost is no object. But is there any tandem racing at that level?

Useful new ideas sometimes spin off the design an impractical concept bicycle — but in this case, in my opinion, they would relate the ride quality and durability of the unusual frame, rather than to the shaft drive.

I recently received a membership solicitation from the Boston Cyclists’ Union — the new kid on the block in Boston Area bicycling advocacy. The image of a family happily enjoying travel by bicycle is printed on the envelope:

Here’s the image. How, uh — sweet.

The child is in a front-mounted child carrier, which I find distressing in itself. it can impair pedaling and steering, and if the bicycle has a head-on collision or something stops the front wheel, the kid can vault over the wheel and go down headfirst. I know that this kind of child seat sees some use in Europe, but on the other hand, the more modern and safer approach is to use a cargo bicycle or tricycle (“bakfiets”) with the child in a low compartment ahead of the adult rider — or a bicycle trailer. Even a rear-mounted child seat is less risky, despite the instability it causes.

Well, yes, they are all wearing helmets — though both Mom’s and Dad’s are tilted back on their heads like sunbonnets.

But also, Mom is riding on the bicycle’s rear rack. Consider the effect on stability, or her getting a foot into the spokes of the rear wheel. For good reason, it’s illegal to ride on the rear rack. This is from Massachusetts General Laws, Chapter 11, Section 11B, the bicycle section, and is typical of law all around the USA:

(2)(i) The operator shall ride only upon or astride a permanent and regular seat attached to the bicycle; a passenger shall ride only upon or astride a permanent and regular seat attached to the bicycle or to a trailer towed by the bicycle.

Why doesn’t Mom for crying out loud have her own bicycle? Or maybe they could get a tandem?

Why does Boston Cyclists’ Union try to recruit members by showing anything so stupid, hazardous, and illegal?

I could comment on the quality of the artwork as well, but I’ll demur on that.

This letter is one for the circular file.

I’m writing about a Web page on a Web site of the British organization Sustrans (“Sustainable Transportation”). The title of the page is “How children lost out to cars in the battle for space on our streets”. Here are two photos from that page, comparing conditions on the same street in 1982 and more recently:

That’s quite a change — but was there a battle?

I am moved to state a different opinion. Sure, it’s OK for some streets to be play streets. A street hockey goal often resides on the dead-end street where I live, and that’s fine. Inline skates wouldn’t roll on grass, and the puck wouldn’t slide, either. On the other hand, the collector street that leads down a hill out of my neighborhood isn’t an appropriate place for children to play, and never was.

The Sustrans article doesn’t make that kind of distinction.

Try cycling on any popular rail trail and I hope you’ll notice that bicycle speeds which optimize travel times and provide exercise for fitness are not safe where children wander. My bicycle is not a toy for play in the street, it is a tool for transportation, exercise, sightseeing and riding in the company of friends. For that I need streets where rules of the road apply. Turning a blind eye to the problem with bicycling on play streets is one of the more annoying aberrations of populist bicycle advocacy. To me, it is one more aspect of the fabled toy-bike syndrome, and also would go so far as to make motoring more difficult by putting children in the way of motor vehicles.

Certainly, the issue is a bit different in Europe, where urban streets were laid out hundreds of years ago, many are narrow and lack sidewalks, and urban residential areas lack play space. There, streets must more often double as play space. In most North American cities, there is less desire for play streets because there is more space for children to play, without playing in the street.

Characterizing the assignment of street usage as a battle strikes me as skewed, because, at least on local streets like the one in the photo, we would then be talking about residents’ doing battle with themselves. Some of the children who played in the street 20 years ago are the adults who park cars there now. The change in use of the street occurs incrementally — one car parked on the street, then two, etc. The resulting reduction in the quality of street life is slow decay, not a battle.

It’s different, or course, on main streets where the decay is due to through traffic which turns a formerly quiet street into a “traffic sewer”, or where neighborhoods are gutted put a highway through. In that case, residents often do battle with non-residents.