Category Archives: roads/streets

2020: A Year of Bicycling Backwards

The corona virus (COVID-19) pandemic has had many devastating impacts, from death or long-term health issues for too many, to economic hardship, as well as some supposedly “silver lining” effects. Among the latter, one was an observed trend in a number of places around the world of increased numbers of people bicycling.

Violinist Christian Adam, literally bicycling backwards

For me, however, it has led to an absolute cessation of cycling. In that sense I’ve been “bicycling backwards” in 2020, with respect to what is sometimes called a boom in cycling for many others.

That decision on my part had to do with a calculation early during the pandemic of the small but not negligible chances of my being in an accident of some sort, and then contracting a potentially fatal virus during emergency care and treatment. That in turn comes from years of experience “sharing the road” (including an accident in 2009) and an evaluation of risks on the streets of my current area – East Lansing and Lansing in Michigan.

Cycling boom?

Increases in use of bicycles for transportation and recreational have been reported since the (northern hemisphere) spring in a number of countries and localities. I’ll list a few representative articles below chronologically for reference and possible later analysis, but one factor that I’m paying attention to is how infrastructure for cycling figures in the trend (which I’ll discuss briefly further down).

Infrastructure a conditioning factor

Much as there’s a trend to more cycling, there is also a block where infrastructure is insufficient. It seems that most of the places where we have seen increases in use of bicycles this year are those where bike lanes and paths are relatively safe and their networks well-developed.

There is significant research indicating a correlation between good bicycle infrastructure and numbers of people who cycle.1 And there’s also research indicating that better infrastructure – especially physically divided lanes – favors both more people biking and their safety (as well as being better for car drivers).2 Type of infrastructure matters, as an article about the latter research notes: “painted bike lanes provided no improvement on road safety.”

Numbers in safety?

Also, it sounds like the “safety in numbers” argument has it backwards – the numbers tend to come when cyclists feel relatively safe. So any analysis of the current boom in cycling should dig deeper into where the boom is really happening, and what people’s feelings are about biking there relative to places where bike sales may have been up earlier this year, but actual biking numbers maybe fizzled after the initial enthusiasm wore off.

Although the area of Michigan I’m currently in does have some bike trails that are mainly suitable for recreation, the major effort to provide for cycling here has been in the form of bike lanes demarcated by painted lines and signage. That’s not insignificant, involving sometimes a “traffic calming” measure of reducing a four-lane road to one each direction, a middle turn lane, and bike lanes by the curbs, which can be unpopular with car drivers. It’s a step in the right direction, in my opinion, but still leaves cyclists exposed when for whatever reason the sharing doesn’t work as planned.

In any event, I did not see a noticeably higher number of cyclists on the road here this year.

ER improvements?

As indicated above, my decision not to bike last spring was premised in part on uncertainty about conditions in emergency rooms (ERs) during the early stages of the pandemic. One deals with risks in biking as a matter of course, but this was for me a tipping factor. It may be, with better understanding about COVID transmission and how to slow or prevent it, time to adapt the layout of the facilities, and more availability of personal protective equipment for medical staff and patients, that ERs now are safer in this regard. However, I still wouldn’t want to tempt fate.

My hope is that with the COVID vaccine and chance that we’ll get past the worst of the epidemic and can focus on the more mundane, but important, issues of improving bicycle infrastructure. And I hope to start biking again.

One final note. This past July, my son was out biking and hit a gravelly patch on a turn. He ended up with some pretty nasty road scrapes from the spill, for which I might have recommended a trip to an ER or emergency care facility in normal times. We were able to use a combination of saline solutions, alcohol pads (lucky to find), topical antibiotic, and various bandages over a period of several days, without any infections or other complications arising. (A tetanus booster at the pharmacy, for which he was due anyway, was the only outside intervention.) Thankful for that and that his injuries hadn’t been more serious to start with.

  1. Angela Hull & Craig O’Holleran (2014) “Bicycle infrastructure: can good design encourage cycling?,” Urban, Planning and Transport Research, 2:1, 369-406, DOI: 10.1080/21650020.2014.955210
  2. Wesley E. Marshall & Nicholas N. Ferenchak (2019) “Why cities with high bicycling rates are safer for all road users,” Journal of Transport & Health, Vol. 13. DOI: 10.1016/j.jth.2019.03.004


Zipper-merging & traffic as a system

Texas DOT, San AntonioNorthbound on US Interstate 75 near the Ohio-Michigan border last week, I came to a stretch of highway where road repairs necessitated closing all but the right lane. Cars in front began finding openings in the already slowing lane to my right, and all of a sudden I found myself alone with an empty lane stretching perhaps a half a mile ahead. “Uh-oh, they don’t do zipper merges here.”

The problem of merging traffic

Many years back, I observed that when two backed up lanes of traffic are merging into one lane, it is always the merged-into lane that moves the slowest, not the lane that is ending up ahead. One might expect the opposite: that the line of cars in the lane that is ending would move more slowly as drivers try to move into the active lane of traffic. But what in fact is happening is that everyone in the ending lane is trying to merge early at different points in the active lane. And that seeming politeness or prescience actually helps slow the whole process down for everyone.

Car traffic is a system – a fairly linear system, so not too complicated in how it works. However it has properties beyond what the individual driver in its midst can see, and which are unknown to him/her. For example, in heavy but moving highway traffic, if one driver slows by stepping on the brakes, all the drivers following will also have to touch their brakes at that same location for a period of time – even though the reason for the first driver tapping their brakes has long since passed. One name for this is a “traffic wave” (a simple interactive model online shows how it works). I witnessed that phenomenon from an office building overlooking US Interstate 5 one early evening in late 1978. Once you see traffic movement from well outside the driver’s point of view, driving it is not the same.

Zipper merge, aka late merge

Minn DOTI never really thought more about merge dynamics until having to deal daily with one particular highway merge – where Virginia State Route 267 eastbound joins US Interstate 66 – on a commute home in late 2010 and early 2011. The heavy traffic would always be backed up more or less as the two lanes from the 267 spur fed into 66, and the rightmost of those lanes ended.

Of course the same phenomenon mentioned above reproduced regularly, with the merge-into lane – the left one in this case – moving slowly and people trying to pull their vehicles into it at the first opportunity. Except, that is, for a few cars zipping along down the empty right lane and merging up ahead.

Knowing this particular road, I tended to “precrastinate” and be in the left lane well before the merge dynamic began. Then I noticed that if I let someone in early, I might also have to let someone in later on. And there were other dynamics one observed, like the driver ahead letting everyone in in front of him/her. Or in the right lane someone fully stopped well before their lane ended, with their blinker on and a tail of stopped traffic behind them.

I ultimately adopted the tactic of letting no one merge in front of me until the right lane ended (by managing distance, one reduces the perceived opportunity to merge), and then always letting someone in at the merge-point. It was later on that I learned this late merge dynamic has been dubbed the “zipper merge.”

Turns out that in heavy traffic, zipper merging – cars using both (or all) lanes and alternating where one lane ends – can “reduce traffic backups by as much as 40 percent.”

Who’s being polite?

In the US, waiting your turn in line is part of the culture. Cut in a line of people waiting to get to or through something, and folks disapprove, grumble, and maybe publicly mutter their opinion of your action or character. This social norm is functional in many situations such as ticket windows and cafeteria lines.

Highway traffic is different because you can’t do a U-turn to go back to your proper place at the end of the line and wait your turn (imagine the traffic consequences). So drivers tend to want to do the next best thing, which is to merge into the line in the first opportunity. At least that’s better than trying to cut in at the head of the line, right?

For their part, the drivers in the merge-into lane accommodate early merges – after all that seems reasonable and they’ve been on the other side too.

So what you end up with is the dysfunction I observed already years ago: the merge-into lane moving more slowly, and the merge from lane mostly empty except for cars slowing down to merge a soon as they can. And the occasional vehicle zooming down the merge-from lane and out of sight.

Minn DOTThat dysfunction is heightened to the degree that early mergers feel offended by the seeming impoliteness of late mergers (for example, see discussions from 2016 & 2017), and compelled to enforce denial (blocking at the merge point or straddling lanes). This was the potential scenario I had to consider on I-75 the other day, having already passed a lot of early mergers already.

Flipping the norm

Some of the online content about zipper merging plays off the dominant notion that it seems rude:

Apparently efforts to re-educate drivers on this point are having mixed success, at least in the US. My impression is that zipper merging is gaining some traction in the Washington, DC area, but it clearly was not used on the road to Detroit. (A 2016 Business Insider article highlights the experience in Missouri, Kansas, Washington, and Minnesota). From a cursory look at info on other countries, it’s not clear that people in general take that readily to the concept.

Aside from public education, improved signage (either promoting zipper merge or simply not indicating which lane will be closed until later), there are even some efforts to educate children (future drivers). It may take a while to change prevailing attitudes, but it might help to frame the issue in terms of traffic as a system, with dynamics you can best understand by stepping outside of your role as a driver (incidentally the kind of perspective that would inform programming of self-driving vehicles). In the meantime, unfortunately, one can’t expect that trying to use the more efficient zipper merge will necessarily be met with approval.

So on that stretch of I-75, I ultimately played it safe and found a gap in which to semi-early merge. Then one other vehicle sped past to the merge point – and I may have been the only one who didn’t mind.

Sources of images: Texas DOT, via Blogspot (top); Minnesota DOT, via Reddit (middle); Missouri DOT, via Twitter (lower)Facebooktwitterredditpinterestlinkedintumblrmail

Çatalhöyük & a line from Kōbō Abe

In the Neolithic town at Çatalhöyük in what is now south-central Turkey, “The houses were … built so close to each other that it was impossible to pass between them. … It’s thought that the roofs of the houses provided the paths and sidewalks to traverse the community.” This description by Prof. Steven Tuck in his “Cities of the Ancient World” course, called to mind a passage somehow remembered from a translation of Kōbō Abe‘s Red Cocoon1:  “I slowly walk along the narrow crack dividing house from house ….”

Rendering of mural in Çatalhöyük that some say shows nearby mountains and a kind of map of the community. Adapted from Image by: Schmitt AK et al. Source:

I don’t recall reading the rest of Red Cocoon but the image that sentence2 evoked was of some slightly surreal cityscape where one could walk along the flat roofs of adjacent dwellings inhabited by mostly unseen people. Perhaps that image was shaped by memory of the scenario in another one of Abe’s works, Woman in the Dunes, where the main characters (one unwillingly) were confined in a space below a barely known community above. Or perhaps by my brief experience on rooftops in Djenné, Mali, even though the houses I lived in were not connected and (unlike the solitary wandering and wondering of Red Cocoon‘s protagonist) there was a certain social nature , although somewhat circumscribed, to that level of city living.3

Artist’s impression of Çatalhöyük. Image credit: Dan Lewandowski. Source:

In any event, here was a city that, strangely enough, seems to have been laid out along lines similar to what I’d once imagined from Abe’s line about “the narrow crack dividing house from house.” Çatalhöyük’s particular organization of habitat (bunched together so that one entered each one from above) and social space (the adjacent roofs of the nearly joined houses), doesn’t conform with basic assumptions we have about the fundamental layout of living space and community. And it raises a number of questions, many of which – about why people pioneered urbanization in this place, and how their town worked – have been examined by archaeologists such as Prof. Tuck.

One question that interests me is whether “street” (as opposed to path) hadn’t yet been invented – rather analogous to the concept of “zero” in mathematics. People knew probably all too well what “nothing” was, or wasn’t, but it didn’t have any practical use once you had something that could be counted. Perhaps similarly, anyone could see that there could be a space between two houses, but maybe it didn’t occur to use that for anything other than another dwelling (which would have the advantage of keeping the continuity of roof spaces above, and eliminating the risk of people or things falling into the gap).

Obviously imagining a lot here, but the idea of streets as something that had to be thought of has actually been discussed regarding a much later period of history. In an essay entitled “The Discovery of Streets,”4 J.B. Jackson takes us from the ancient but definitely post-Çatalhöyük small city with its “flexible and informal network of alleys, blind alleys, flights of steps, and paths,” through the evolution (focused here on Europe) of markets and spatial needs, to the eventual use of streets in planning and reshaping communities (which he ultimately connects with the freeway, which I always associated with paths and old turnpikes, but that’s another subject). The turning point he sees as having happened in 11th century Europe:

the discovery of the street as a determinant of city growth and development had by the end of the century produced increasingly orthogonal town patterns, based on right angles and perpendicular lines …

So it does seem as if one could also suggest an “invention of the street” or perhaps “discovery of the alley” some time after Çatalhöyük. And by extension, that perhaps there might be concepts of urbanization that we, for all our sophistication, haven’t yet thought of (or maybe even contexts in which the ancient model from Çatalhöyük might turn out to be useful).

Returning to Abe’s walking along the “narrow crack dividing house from house,” with benefit of Jackson’s discussions of space in Old World cities, there is another interpretation (which likely was obvious to other readers): the “narrow crack” was in fact a narrow street between rows of houses. But it still was more fun to imagine it the other way.

1. Japanese title: 赤い繭 (Akai Mayu), published 1950 or 1951. There have apparently been two translations into English, one by John Nathan in 1966, and the other by Lane Dunlap in 1987. Needless to say, Abe’s story line goes in an entirely different direction than what preoccupies me here.
2. Retrieved from Abe’s obituary in the New York Times (23 Jan. 1993). I did not find the story available online.
3. During the hot season, people would often sleep on their roofs – but when you wake up in the morning on your roof, you always ignore neighbors who are awakening on theirs (in general one never says “good morning” to someone before they’ve had a chance to at least wash their face and take care of their morning essentials anyway). Also one doesn’t peer over the edge of one’s roof into the adjacent courtyards. As such this was different rooftop environment than either Çatalhöyük or what I imagined from that line in Red Cocoon.
4. J.B. Jackson, “The Discovery of the Street,” in N. Glazer & M. Lilla, eds. The Public Face of Architecture: Civic Culture and Public Spaces, The Free Press, 1987. An article in The Atlantic about this essay by Charles R. Wolfe – “City Life: Revisiting J.B. Jackson’s ‘The Discovery of the Street’” – is a useful complement.

A Vienna bicyclist – epilogue

After 8 months of regular and sometimes intensive bicycling in and around Vienna – even through the cold months of winter – my number came up: I was hit at about 7:30 a.m. on April 28 by a car making a right turn on a red light (legal in Virginia). The rest of the details aren’t necessary here except to say that the significant injury was a fracture to the tibial plateau on the leg that the car hit (fortunately no worse a break and now seems to be healed), and resort to legal means resulting in a settlement.

I am very grateful to the doctors, my lawyer, and especially the two people who came forth after I had to advertise for witnesses. The incident was somewhat of a jolt, first for the accident itself and the injury, and then for the way the driver handled it. The fact two witnesses did come forth was extremely encouraging during what otherwise was a very difficult time.

I am not sure about the percentage of bicyclists who have an accident with a car at some time during their life, but some old statistics on bicycle-related injuries (not only accidents with cars) estimate that 1 bicyclist in 20 is injured every year and that on the average, a bicyclist will have a minor injury every three years and a serious one every 15. And per mile of travel, cyclists are 4.5 times more likely to be injured than motor vehicle drivers.

As far as car-bike accidents, a study in Toronto, Ontario showed that bicyclists caused only 10% of car-bike accidents (which apparently is much less than popular perceptions). And the bicyclist is always much the worse off for the encounter (same thing with motocyclists). Whatever the case, as a bicyclist it is worth going to a reasonable extreme to verify what a driver *might* do, and to try to make eye contact with them.

The experience raises a question for me about how practical the slogan of “share the road” is. Driver error, or cyclist error (or road problem affecting cyclist speed or trajectory), and the cyclist loses – paying dispropotionaltely more than ther driver, no matter what compensation the latter may possibly receive.

Well-demarcated bicycle lanes are a minimum for major roads. Maybe also there is a safety in numbers – more cyclists will get more attention and respect. I also used to bicycle in Chengdu, China and was grateful for bike lanes separated by curbs (even though these lanes have been narrowed in recent years to widen the main roads) and for the number of other cyclists around when crossing most major intersections.

On the other hand, even in a city like Denver, Colorado – a community with a lot of cyclists, apparently good bicycle infrastructure, and awareness on the part of drivers – has noted that with more bicyclists, there is an increase in serious injuries from accidents with cars.

The whole thing has also prompted some increased caution when I am behind the wheel. In any event, we have moved so I am no longer bicycling in Vienna, nor for the moment anywhere else. When the circumstances are right I hope to do so again.

Oh – and I was wearing my helmet (funny how many folks asked about that).Facebooktwitterredditpinterestlinkedintumblrmail

Reflections of a Vienna bicyclist

For various reasons, I’ve been doing a lot of bicycling over the last few months in Vienna. No, not that Vienna (dream on), rather the one in Virginia, not too far from Washington, D.C. This has me thinking about a number of things: transportation, energy, environment, sociology of bicycles, etc.

In this season, bicyclists really stand out. But even in the warmer weather I did not note very many in Vienna. Judging by the car to bike ratio locally, the estimate that 1% of all trips in the US are by bicycle seems high.

Whatever the numbers, there are some particular patterns to where one does and does not see bicycles in Vienna, and what kind of bicyclists. To begin with, I’m tempted to contrast two routes in Vienna. One of these is more affluent, running mainly along the Washington & Old Dominion trail (W&OD), serving mainly recreational and sports cyclists, and probably a few who use bicycles as part of their commute to work (though those would seem to be very healthy commutes judging by where W&OD approaches Metro stations in Dunn Loring and Falls Church to the east or office parks in Reston to the west).

The second route is less affluent, running on the sidewalks of main commercial road, Maple Ave./Chain Bridge Road/Rte.123 (the road itself seems much too risky for bicycles), and serving mainly people who are going to local jobs. (Noting mention of bicycles as “a common mode of transportation” for day laborers elsewhere in northern Virginia, this demographic in Vienna could be researched further.)

The two routes intersect in the center of Vienna town (on the town map these make an X with one thick red leg and one thin green leg). One sees more bicycle helmets and spandex on the W&OD – and more bicycles overall when the weather is good – than on Maple Ave.

There are not a lot of bicycles off of these two routes from what I’ve seen, though some people bike to the  Vienna Metro station which is a couple of miles to the south (the 54 bicycle rack spaces were full on the rare occasions I checked – don’t be impressed as there are 5800 car parking spaces there which fill up quickly each day). I generally take the Maple Avenue corridor, or some quieter sidestreets that roughly parallel it, and encounter only occasional adult or youth cyclists on Maple, and rarely children bicycling on the side streets.

Bicycling in the US is not as common as it is in some other parts of the world, and indeed some of the infrastructure disfavors bicycling. The W&OD trail is a unique resource in this regard (some other urban areas in the US have similar trails on old rail right of ways), privileging Vienna and some neighboring communities. Apart from that there is not much – Virginia apparently ranks 45th among the 50 US states for funding of bicycle and pedestrian projects, so maybe I’m reporting on the low end of the spectrum in the US.

Aside from the classes of bicyclists I discern on the two routes in Vienna, the age dimension is worth noting. One essay puts it this way:

In America, bicycling appears to be an unacceptable activity for adults. It is viewed as a pastime reserved for children (people who are not old enough to drive cars). Adults who sense they are violating this stricture, excuse their bicycling as the pursuit of physical fitness, referring to their bicycling as training rides. … Some also refer to themselves as serious cyclists, a term used to describe riders who, typically, keep track of pedaling cadence and other bicycling statistics, thereby giving proof that their riding is not child’s play. (quote from the FAQ Archives)

It’s hard to tell what the attitudes are in this regard in Vienna, although it’s clear that not a lot of adults are biking – especially off the recreation-friendly W&OD trail. On the other hand I haven’t noticed that many kids on 2 wheels either. Also, from what I’ve experienced, Vienna drivers generally are quite courteous to bicyclists – certainly no behavior one could interpret as a negative judgment on the appropriateness of someone my age on a bicycle. And in one store, a younger cashier asked if I was biking for environmental reasons – for some it may even be a bit cool (although the weather lately has taken that all the way to downright cold!).

On the individual level, one of the big reasons to bike rather than use the car is the savings in gas money. Fitness too is a benefit (why drive to a fitness club where you pay to use an exercycle?). Environment might be a motivation too, but it should be a factor on the macro level on which planners operate.

Bicycling may not be appropriate for all people and in all situations, but more people traveling on bicycles instead of cars (at least for shorter errands) could have benefits both in terms of lower national consumption of fossil fuels, and improved public health.

In all the talk in the new Obama administration of improved environmental policies and of increased expenditures for infrastructure, could bicycles and bicycling be given more attention as an area to develop? Hopefully the advocacy groups in this area like Bikes Belong , the League of American Bicyclists, and the Thunderhead Alliance will make this point. What about a goal to get the US closer to European or Chinese levels of bicycle use (though in China there has been a trend to more use of cars in recent years) – say moving from 1% to 5% of trips on bicycle rather than cars?

Back again to the local level, what would it take to get Vienna, Virginia to use bicycles more?Facebooktwitterredditpinterestlinkedintumblrmail