Category: bikes

Safety in numbers, gaps in risk environments, and bike helmets, Part II

Lisa Schweitzer

If I’d known I could so thoroughly piss off the Smartest Boy Urbanists merely by suggesting that I like bike helmets AND better design, I’d have done so sooner. And louder. One was particularly outraged and sent me roughly 90 emails (ok, 7). I was told I was wrong roughly 490 times, which is interesting because I feel like didn’t really come to any conclusions other than “gosh, these data aren’t really all that helpful, and I like it when people do not get head injuries.” But one of the great skills of the Smartest Boy Urbanists is that they know you are wrong without reading what you wrote or listening to what you said, so we’re good.

I did suggest that I very much doubt that helmet-lovers like me are the reason that most American cities aren’t turning into Amsterdam particularly fast. I’d put that down to our general tendencies in urban and social policy (towards less competence rather than more) in every policy domain rather than dowdy old me with my helmet. And the very real possibility that land uses do not change as quickly as we might like.

There is a difference between these questions:

1. Are you, Bob the Cyclist, as an individual better off with or without a helmet, right now, in the streets you bike in, not necessarily the streets we would like you to have in order to lower your chance of a incident to virtually nothing so that anything like helmets designed to protect you in case of incidents you won’t have in that better bike environment become irrelevant?

2. Might mandating helmets suppress “Safety in Numbers” (SIN), because people do not like to wear helmets, so much so that their reticence cancels out the SIN effects (and worse, discourages cycling so much that people won’t cycle and thus get the exercise benefits)?

Keep in mind, I am not advocating for mandating helmets. I am asking questions, particularly, about #1: in the matter of “should I wear a helmet and/or have my kid put one, too”… should you equip like you are in the city you want, or should you equip for the city you have?

Because if the city you have is badly designed, I think it could be pretty irresponsible for urban experts to tell people that helmets are dumb because Amsterdam! Helmets may, in fact, be dumb because Amsterdam!, but most of us do not live there, and there is a big gap between many–not all certainly–but many existing cycling environments in US cities and what Amsterdamians enjoy.

If you tell people to get out there and bike “for numbers,” there’s a time period, as the numbers build, where you are pushing people into existing crash risks for your agenda and using them as a means to your end. Somewhere between “not enough bicyclists to reduce crash incidents so low helmets are irrelevant/current conditions” and “enough bicyclists to be visible, displace cars, and make life safer for cyclists” there is a gap of time where the risks might well go up–particularly for inexperienced cyclists, which includes kids–and who, exactly, is supposed to take those risks on for the sake of getting us the numbers we need?

Is that time period and subsequent gap in the risk environment important? I do not know. How much more cycling would we need in order to push through that gap? Dunno. We have some good modelings studies, but models are models and a well-designed empirical study can invalidate a million modeling studies.

Granted the needed bike density threshold, whatever that threshold might be in various contexts, how much time would it take to get it in local contexts? Dunno.

Now, before all y’all scream and yell that this gap is no reason not to pursue numbers, that is not what I am suggesting or exploring here.

But I do think that gap is something we can’t just assume away as unimportant while we look down our noses at helmets because in Amsterdam, things are so safe for bicyclists that helmets are silly. I personally approve of many things in and about the Netherlands we don’t have in the US for all the reasons we in the US can’t have nice things.

If that gap is meaningful, the policy and planning recommendation (as opposed to the individual equipment strategy) is probably to go after car drivers with policy (such as price floors on gasoline) to decrease volumes immediately to give bicyclists in existing urban environments a fighting chance to get out there, even with urban environments as they are. Policy changes can occur more quickly than built environment ones, but…I know. Getting such a radical policy change is beyond the scope of what I can imagine for political feasibility. It’s too bad.

We don’t talk about the policy environment in Denmark or the Netherlands very much, just the design and culture, and you do have to wonder how crucial the policy environment was in securing the ability to make the planning commitments they made to biking.That is, do you get Amsterdam as it is without a $3.80 per gallon excise tax on gasoline? (And do you maintain the ability to tax the daylights out of fuel when you have provided lots of other ways for people to get around?) While I see plenty of advocacy for changing design and increasing cycling, I see very little real movement to discourage car use at high levels, and that tepid approach to dampening car use strikes me as an important blind spot in the gap in the risk environment that I described. Now, I know most people who advocate for Amsterdamishness also think that lowering vehicle volumes is important, but that advocacy has been much less successful than the ability to get bike lanes built, and that means, to me, an evaluation of what is possible/credible/workable granted that sticky problem.

My musings the other day were rewarded by a very nice gentlemen showing me a dream bike and sending me an OECD study where I went through and read a bunch of the bibliographic references. It wasn’t great coverage on the OECD’s part, but they did cite a meta-analysis, and it’s always weird surveying the literature when somebody’s already done it. That said, the brain bucket question is waaaaaaaaay more interesting than you might think:

Hard shell helmets:

  • Risk of head injury decreases by 64 percent;
  • Risk of facial injuries decreases by 34 percent;
  • Risk of neck injuries increases by 36 percent

Soft shell helmets:

  • Risk of head injury decreases by 41 percent;
  • Risk of facial injuries decreases by 14 percent;

Again, none of these are important if you live somewhere where crash risks are so low that subsequent injury or fatality risk is practically nonexistent. But do you live there? I don’t. I live in Los Angeles. It’s going to take us awhile to become Amsterdamesque.

These are from a 2009 meta-analysis, so the study could probably be redone as helmets have changed, and bicycling environments have changed, at least in some places.

This meta-analysis in question appears here:

Elvik, R. et al. The Handbook of Road Safety Measures. Bingley, UK: Emerald, 2009.

I HAD TO GO TO THE LIBRARY IN SUMMER TO GET THIS BOOK. You people have no appreciation how much I sacrifice for you. I give and I give and I give. AND WHAT THANKS DO I GET? Sassing from the Smartest Boy Urbanists, that’s what I get.

I also found a bunch of really nice papers by Rune Elvik in general, and while meta-analysis is often hair-raisingly difficult to do well, accident researchers I find tend to do them in ways that make me say “damn I wish I were that competent” and Elvik does not seem to vary from this general impression.

(ok for some reason my autocorrect wants this name to be Elvis. I promise I have changed it back at least 7 times. So for the record, I am not talking about Elvis. Elvik. Elvis. Sigh.)

It’s never not interesting when there is a conflicting effect. They only had a handful of studies on the neck injury portion, but there are probably more studies now on the neck injury findings.

People have taken stabs at the other question above, but again…I am not convinced we really know much. That said, there are some really nice studies out there, but they show pretty mixed possibilities for Safety in Numbers using methods, the data that are really limited, and most of what we have are pretty speculative modeling studies. (You have to start somewhere, but it’s important to not confuse your start with well-validated empirical findings.)

The strongest claims on behalf of Safety in Numbers article I found was:

Jacobsen, Peter L. “Safety in Numbers: More Walkers and Bicyclists, Safer Walking and Bicycling.” Injury prevention 9, no. 3 (2003): 205-209 (here’s a pdf I found of it.)

This is a strong attempt with severely limited data, but he dug for some good stuff. He’s got walking and biking data for 68 California cities, walking and biking in 47 Danish towns, he’s got bicycling and walking data for 8 European countries, and he has fatality and injury outcome measures. He’s also got data for the UK going back to the 1950s, and he uses a power function to fit relationships between fatalities and relative risks. His best fit is not surprising, the California cities, where he has the most observations. Unfortunately there he’s got to use the percent of the journey to work mode share for biking and walking prevalence. He assumes that those mode shares hold for non-work trips, and while that’s debatable, I don’t really have a better idea for him, and I also don’t really have a better idea than using the percentages even though there is going to be more noise from small cities than we really want in a small sample.

I do have some problems with his power function as he has a couple big outliers in the dataset. A robustness check to address those outliers would have helped me. That said, most of the benefits in relative risk reduction on the California side accrue with really small changes in mode share. That conflicts with a later study, but it suggests that you do not have to have a bike utopia to have real gains as long as enough bicyclists get out there and ride. (Aha! That means we don’t have to accommodate bikes in design much at all, since we just need a few percentage point changes…. AHAHAHAHAHAHAHAHAHAH I AM JOKING. JOKING MIT YOU.)

And I’m not sure I can accept the assumptions about distance and injury; he plots distance per capita against relative risk, and distance is his use measure, and yes, but…I am not sure distance is a proxy for numbers, which is what he wants to show. Per capita distance can go up with relatively few cyclists or walkers who walk relatively long distances or with lots of people on the road making close-to-average-distance trips. Without seeing the distribution, you can’t tell. These are two separate things, and I suspect they might have different effects: the former has longer trips potentially displacing more VMT versus the latter having bigger clumps of people both potentially displacing cars physically and raising cyclists’ visibility to drivers because there are so many cyclists you can’t miss them.)

Again, aggregation to the city or nation-state level–he says he has intersection data but I don’t see any, how did that get passed reviewers and an editor? Am I reading that right?–does not help very much. It could be what we are seeing here is, simply, lower car use. I’m fine with that, btw.

The study that I thought made a nice case for SIN, but it’s an APM model, which means limited parameters and a lot hinges on the assumptions. This is:

Elvik, Rune. “The Non-linearity of Risk and the Promotion of Environmentally Sustainable Transport.” Accident; analysis and prevention 41, no. 4 (2009): doi:10.1016/j.aap.2009.04.009 (I couldn’t find a pdf of that one, sorry…)

Their outcome measure is number of accidents, to both pedestrians and bicyclists. The parameter coefficients come from prior studies. For doubling the number of bicyclists, they do not really see a big effect. The big payoff comes when they reduce traffic by 50 percent, and…that’s a big change, and it’s hard to compare that with what Jacobson finds in relative risk because Rune is examining counts. Do we need a big change in the numbers or a moderate change in the numbers? Rune suggests a pretty major shift in vehicle flow, not the smaller shifts in mode share that Jacobsen’s suggested.

Stay tuned.

This is another APM study:

Schepers, J P, and E Heinen. “How Does a Modal Shift From Short Car Trips to Cycling Affect Road Safety?” Accident; analysis and prevention 50 (2013): doi:10.1016/j.aap.2012.09.004. (No pdf again, sorry. I am a Googling failure).

Schepers works for the Ministry of Infrastructure and the Environment, which strikes me as being better than the Ministry of Silly Walks but not nearly as good as the Ministry of Magic.

This study, like Rune 2009, uses an accident prevention model again, but they have decent data, and APM models are not that data-hungry. They find using the data on crashes from Dutch cities that a mode shift for short car trips to bike trips would have no effect on fatalities and some increase on injuries. This is a good finding for the SIN advocates: without a safety in numbers effect and displacing cars, increasing biking would mean more crashes. It didn’t in this APM. And that’s good because you get the benefits of more biking with no real losses in fatality. If you want gains, then see Rune 2009, above.

Hooray. But. And this is a big one.

They do estimate a substantial increase in the risk of serious injuries from single bike crashes. These can be pretty serious, and a helmet could help with these ones. I suspect one effect embedded in the SIN effect shown in priors is that with good design and welcoming spaces, inexperienced bicyclists get out and ride, which is great, but that includes children, and then we need to get real about what risk and whose risks change, why, and what we should do about it. Kids learn and grow up, but there are new kids coming in and learning the system. Insulating them from major injury, even if it is a single-bike crash, is life-enhancing.

One last one I liked:

Bhatia, Rajiv, and Megan Wier. “Safety in Numbers” Re-examined: Can We Make Valid or Practical Inferences From Available Evidence?” Accident analysis and prevention 43, no. 1 (2011): doi:10.1016/j.aap.2010.08.015.

Basically, they say what I said when I stirred up trouble on Fboo and on the blog. APMs and aggregate spatial units are not an optimal way to figure this out. APMs tend to use spare specifications with volume data for the modes, that’s about it. Aggregate geographic spatial units are not really relevant to biking-motorist interactions in any meaningful way, and so we have no good information about design, only vehicle volumes (which can proxy for design if your design is lowering volumes.)

Only these authors say these things by sounding smart and with evidence and whatnot.

Some excellent papers I read that you might like too:

Wei, Feng, and Gordon Lovegrove. “An Empirical Tool to Evaluate the Safety of Cyclists: Community Based, Macro-level Collision Prediction Models Using Negative Binomial Regression.” Accident; analysis and prevention 61 (2013): doi:10.1016/j.aap.2012.05.018

Wegman, Fred, Fan Zhang, and Atze Dijkstra. “How to Make More Cycling Good for Road Safety?” Accident; analysis and prevention 44, no. 1 (2012): doi:10.1016/j.aap.2010.11.010 FOUND A PDF FOR THIS ONE

This one looks to be very promising in handling the murky mechanism problem I noted with SIN assumptions because they have a cool natural experiment around “cycling season”:

Fyhri, Aslak, and Torkel Bjørnskau. “Safety in Numbers – Uncovering the mechanisms of interplay in urban
transport with survey data.” AVAILABLE ONLINE!! YAY!

Somebody asked me about moral hazard with wearing helmets, so here’s some on those (people are naughty):

Gamble, Tim, and Ian Walker. “Wearing a Bicycle Helmet Can Increase Risk Taking and Sensation Seeking in Adults.” Psychological science 27, no. 2 (2016): doi:10.1177/0956797615620784 (PDF LINK)

This suggests that people compensate with other safety behaviors when they do wear helmets (people are smart):

Phillips, Ross Owen, Aslak Fyhri, and Fridulv Sagberg. “Risk Compensation and Bicycle Helmets.” Risk analysis : an official publication of the Society for Risk Analysis 31, no. 8 (2011): doi:10.1111/j.1539-6924.2011.01589.x

And just to piss everybody else off more…I don’t understand why everybody in planning loves roundabouts; when I am walking around them, all I can think is “Why am I going around this dumb circle instead of just cutting through it? Why did people forget that part of why DuPont Circle is cool? I hate everybody.” This study agrees with me so IT MUST BE BRILLIANT (I am joking, joking with you…)

Parkin, John, Mark Wardman, and Matthew Page. “Models of Perceived Cycling Risk and Route Acceptability.” Accident; analysis and prevention 39, no. 2 (2007): doi:10.1016/j.aap.2006.08.007

So now for those of you who wish to tell me I am wrong, TERRIBLY WRONG…I will summarize my conclusions here:

I got nothing I’d bet my first edition Varian on. But y’all haters do not have much in the way of evidence in support of your “helmets are not a solution, becoming Amsterdam is the solution” position, either. Maybe someday, you will, if people keep poking at the questions and changing streets.

Oh, but I do hate roundabouts.

I come in peace, with a bike helmet on

Lisa Schweitzer

ATTENTION CONSERVATION NOTICE: I come in peace with my bike helmet. Liking bike helmets does not mean I think they substitute for street design or culture, and I really doubt anybody else who isn’t crazy thinks helmets are a substitute for design or safety in numbers, either.

Ok, so brilliant student Shane Phillips (who blogs brilliantly here) yesterday shared something about bike helmets and design, and the piece suggested that bike prevalence is a safety substitute for helmets, and I said, hey, it would work for me if we had both bike prevalence and helmets. When it comes to most things regarding safety, I am more Adrian Monk than Laura Croft.

Note the metaphors there: Adrian Monk is not particularly rational about his assessment of risk. I’m not either. I’ve known way too many people I’ve loved who have been hurt by bike crashes, and one of the worst did not involve a vehicle, at all. I’m paranoid. Every day is a long list of worst-case scenarios that float through my head, and bike injuries are in there with falling meteors and Donald Trump becoming president.

You do realize I think the NFL should change its rules to touch football, right?

So anyway, what I thought was some good-hearted banter turned into a boy urbanist coming in mansplain ABOUT THE FACTS, AND THE FACTS ARE THAT BIKING IS MUCH SAFER THAN BEING A CAR AND SO I GUESS HE TOLD ME.

But I never said that driving was safer. Nobody had. It was an attitude he assumed I had because he wanted me to be wrong, and he wanted to yell and scream and Be the Smartest Boy Urbanist in the Room.

Then another guy piped in, and he at least was polite. But his statements made me uncomfortable, too, because he trotted out the whole “Denmark totally proves that helmets have zero correlation with bike fatalities” conclusion “because almost nobody wears a helmet but there are few fatalities.”

Now, I have nothing against the Netherlands or Denmark, but we can’t use these numbers in this way. I’ve heard my students quote this idea, and while it’s not the worst instance of poor urban numbers, it’s not rigorous thinking about how things might relate.

The idea seems to go something like this:

1) People don’t like bike helmets and that’s what keeps them from riding a bike;

2) Bicyclists are safer when there are more bicyclists are on the road (“the safety in numbers” effect); and thus

3) If helmets keep bicyclists off the road, they do not improve safety because they dampen the “safety in numbers” effect.

Now, most people can understand the reverse causation possibilities in 2: bicyclists are safer where there are more bikes and it’s likely there are more bikes where things are safer, either because of design or culture or both, which is what we likely see in Amsterdam.

And then the corollary: the more bikes there are, the fewer cars there likely are, and the lower fatalities are more likely to occur because of the latter, not the former. The former is a lever for the latter, but they are still two effects.

That part, I totally buy. It’s the helmet part I’m having trouble with. Why? Because for years I’ve advocated for and studied transit, and I’ve heard people tell me every specious excuse in the book for why they don’t take transit. Them: “It doesn’t come near my house.” Me: There’s a bus stop on the corner, a five minute walk.” Them: “Oh, but that’s a bus. Buses take too long.” Me: “It’s a 15 minute trip, you have no transfers.” Them: “It doesn’t leave when I want it to/the sun gets in my eyes/I’m allergic to the bus seats/people look at me funny/I got sick on a bus once after drinking seven bots of tequila so I just know I get bus sick.”

So if you aren’t riding a bike because you don’t like wearing a helmet, then you are a fair weather bicyclist in my book. “It messes up my hair.” Buy a comb. And what? You don’t ride if it’s windy? When I actually get my fat self on a bike, which isn’t often, and I’m not wearing a helmet, I always wind up looking like I did my hair with an immersion blender anyway. Hair, schmair.

Now, in fairness, I do understand the problems that people have with helmet laws. So you forgot your helmet, and then what? You get a citation? That’s a hassle, just like having to have exact change for the bus is a hassle. But how strictly are helmet laws really enforced? Anybody got an idea on how strict enforcement is in places where they have helmet laws?

BTW, I don’t think helmets should be mandated because it just strikes me as overreach. That’s different from wishing people would wear helmets.

More to the point about research, I can find no believable research that demonstrates “safety in numbers” results from not encouraging helmets, and I also can not find any credible data that “safety in numbers” precludes wearing helmets or that helmet laws discourage street design, or any other such thing.

Here’s the story that circulated on Streetsblog, where the columnist, Angie Schmitt, who is really a wonderful columnist I often read for Streetsblog, concludes things I really don’t think you can with the numbers from the graphic she presents.

Let’s start with the title. I know titles are always screwed up, but the title starts us off in ways that make me squirm. Helmets are not the answer the bike safety. Well, did anybody say they were “the” answer? Can somebody point me to the article or expert saying “We don’t need bike lanes because we have bike helmets?” Is somebody saying that? Did Congress slash funding for bike facilities because we have helmets now? Because that would be crazy if people believed those things, and I’m willing to believe that some people say this because some people also think that aliens embedded a code in the Torah. But…really?

Then there’s the next line:

Better street design and getting more people on bikes — not blind faith in helmets — are the keys to making cycling safer, recent research has shown.

Are there people out there in the world telling people that all they have to do is put on a bike helmet and they should be fine, just fine, even if they peddle themselves onto the 405 when traffic is moving at 60 mph? Because that would be nut bar. Who is this person, or these people? Or this just shadowboxing to set up a column?

Just about everybody who does safety research groks that safety isn’t a one-factor deal, except when it comes to very simplistic things, and mobility systems are not simple. Seat belts are fine, but seat belts, crumple fenders, and airbags are a whole package. Seat belts, crumple zones, airbags–and speed limits and proper sight distances and drunk driving education are still yet more potential dimensions and variables.

You know what else increases vehicle safety, a lot? Using cars less overall. I’m a fan of that one, too. But that doesn’t mean I think we should get rid of airbags.

Granted this, why do some US bike advocates seem to think that if you favor wearing helmets, you are against good bike design? Why can’t people have both?

The logic strikes me as a bit like this: You think people should eat right. YOU MUST BE AGAINST EXERCISE THEN. WHY DON’T YOU PEOPLE WHO WANT TO EAT RIGHT UNDERSTAND THE IMPORTANCE OF EXERCISING JEEZ? Shit, some people hate to exercise, and if you associate exercise with eating right, people won’t eat right because that means they’ll have to exercise.

Um, no, it’s possible that both are a good idea, and that both contribute, even if one effect is more important than the other.

Just like it’s possible that there is a “safety in numbers” effect and a helmet effect on safety.

Then we move into the rest of the column, which shows this graphic, which is supposed to show us that bike helmets do not contribute to safety because look at

Cj L75WVEAADWl 1

This graphic, like the one one she references but does not display, I think came from Toole Design Group.

Now, Schmitt grants that these are only eight data points, but then goes on to say:

Of these countries, the U.S. has the highest rate of helmet usage among cyclists — around 55 percent — but also the highest cyclist fatality rate per distance traveled. Meanwhile, in the Netherlands, where helmet use is practically nil, cycling is much, much safer.

While this is just eight data points, higher helmet use seems to be associated with higher fatality rates. Intuitively, that makes some sense. The more dangerous an activity, the more people feel inclined to take steps to protect themselves.

So the url says this is “why helmets are not the answer in one chart”…but this had better not be the basis for the conclusions because this chart does not say anything consistent about anything. Technically the charts shows sixteen data points, for the anal data types, and 8 cases.

One point of contention: helmet use is not practically nil in Denmark–her idea of practically nil and mine are not the same; and with helmet use, I suspect that there are strong nonlinearities by age, cycling experience, and gender. You don’t necessarily need everybody wearing a helmet. It may be that the Netherlands has the right people wearing them, while all the low-probability injuries and fatalities types go without. Sure, it means not everybody wears a helmet, but it also could mean that in individual incidents, helmets help.

But I digress. The major point: why are we highlighting Denmark/Netherlands and the United States here? Because if I want to make the opposite claim–that bike helmets clearly do help with safety–then I have those data in the chart, too: compare Finland and the UK. Or Finland and France.

If you wanted me to do actually my job here, as a researcher (ugggghhhhhhh work), I’d say we cannot use these data, at all. They are noninformative about correlations because aggregating bike safety at the national level isn’t really useful. Nation-states do not represent biking environments or cultures, per se.

We all know that the US has poor infrastructure and design for bicyclists in many US cities, and since Denmark and the Netherlands are highly urbanized, you can maaaaaybe use the nations as proxies for bicycling environments there. Maybe. But as some cities in the US improve their design, the US as whole becomes a very poor proxy. Even as it is, freight volumes and practices differ, weather, etc etc between Denmark and the US, and it’s hard to compare rates across a big country and small country because small countries are always going to have more variation in aggregate numbers than the big ones. I don’t think large numbers problems explain the differences between the US and the Netherlands and Denmark–I think the latter’s planning clearly demonstrates effectiveness–but it does make measuring the effect more of challenge.

We also have the problem that fatalities might be even lower than they are–closer to my practically nil than Schmitt’s practically nil–if the Dutch wore more helmets more frequently. The comparison that matters is between helmet wearers versus non wearers in Amsterdam. As one commenter noted: “Show me a statistic of fatalities of helmet wearers who crash on protected multi-use bike paths.”

THAT is the world I want to live in: helmet wearers wrapped in bubble wrap riding great bikes on great bike facilities. Maybe we could even have some these cool bubble jobbies to wear when biking:

Bubble soccer USA Rent Bubble Soccer
(Image from http://www.bubblesoccerusa.com; God that looks fun.)

What matters are the practices and designs in place. In order to know what we’d like to know about the independent effects of design and helmets, we need to know about specific intersections, specific street set ups, specific traffic conditions, and specific crashes.

And that’s a huge problem. Because–and this is a good thing–bike fatalities are statistically rare events, even in the US, which means doing the sort of research you’d like to do–controlling for all the design and personal safety factors (like wearing a helmet) that enter into fatalities–requires data usually too sparse to grant your statistical analysis the power you need to find effects.

The other problem with these conclusions is that helmets may not be useful in preventing fatalities, but they may be useful in preventing injuries. Injury prevention has social value, too; and it may be that “safety in numbers” would also influence injuries for the better concurrently with fatalities, or it may be the opposite, just like on some freeway lengths, lower speeds are associated with more crashes but fewer fatalities. (Congestion lowers speeds, therefore decreasing severity but increasing frequency.) I am betting bike-related injuries follow similar nonlinearities into zones where you might have more frequent incidents (bike-ped, bike-bike), but that those incidents are not as severe as what happens when there are too damn many cars moving too fast.

The other study that Schmitt highlights is better, but still has some pretty troubling data problems Here is a pdf to the study. This is a very nice study, and the authors are explicit: they state they inferring and do not have causality, and–and I think this is interesting–gender winds up being a significant variable. I am not sure I understand their interpretation, but maybe I will see it more clearly when I reread it.

The problem here–and I’m not saying anything the authors do not know-is that they use bike helmet laws as a proxy for wearing bike helmets, and that is not optimal. They may have no other choice, but self-reports are a problem. It is a truth universally acknowledged that human beings are bad self-reporters, on everything, but particularly when they know there is a “right” and “wrong” answer, like safety and health questions.

They are two steps removed from being able to make policy conclusions about helmets. First, do helmet laws increase helmet use, and then bicyclist who experience trauma wear helmets? And another problem: if bike helmet laws do suppress use, it would exert an effect both on overall amounts of cycling which is likely to (though not inevitably) lower incidence and on the safety in numbers effect. The endogeneity problems make things tough, right along with the rarity of the event that prompts people to aggregate the data to non informative spatial units.

Again, we go back to the problem of really wanting to be able to look at specific traits–of places, people, behavior–of specific crashes and compare them with nonfatal incidents in those locations as well as overall exposures at those places to avoid the Abraham Wald survivorship problem .

Keep in mind that I am not saying that we do not need better bike design. Bikes and bike facilities more than warrant priority. People enjoy them, they promote health, and they do not cost very much granted what they can deliver in terms of mobility and enjoyment. Promoting cycling and walking are no-brainers. Do I think they solve climate change? Eh, maybe. Not convinced. But if people enjoy these activities, then why wouldn’t we make space for them cities based on that rationale alone?

Schmitt’s last comment is what inspired me to write the blog post:

Despite the high rate of helmet use in the U.S., helmet campaigns have clearly failed to make cycling as safe as it should be. If anything, they’ve distracted from the much more important work of designing safer streets and reducing motor vehicle speeds in cities.

Now, wait. Suggesting that you slap a helmet on your head, which takes all of 30 seconds, distracts the US from doing a good job with bikes? Come on.

Really, folks, people like me are not your enemy. I just want you to keep the skin on your face where it is if you get unlucky one day. If you don’t want to wear one, well, that’s up you. But just like the people who love me wish I’d lose weight, I want you to ride safe, too. I want you to do what you can to protect yourself as US cities try to get their shit together and supply better spaces for riders.

Bike lanes and bike babble, in context

Lisa Schweitzer1 Comment

Every so often, people get mad at me for rolling my eyes at my profession and the fuss we make over bike lanes, which always winds up with somebody lecturing me on how bike lanes save the universe, and…Copenhagen! Davis! Portland! Oh my.

1. I have nothing against bike lanes. Nor do I think they save the world. Or cities. But we should have them anyway. They are an amenity that increases the choices and options available to people; they make places better. The people who use them enjoy them, tremendously. They are an inexpensive way to add value to streets.

2. Thus they are a no-brainer. I don’t spend a lot of time advocating for bike lanes and other amenities for the same reason (I think) that the bike loudmouths don’t advocate for pedestrian amenities–we both assume that these things should be the default, and every time we go out to redevelop, these amenities should get put in without a lot of question and hooptydoodle because they are a standard urban amenity that we put in every redevelopment plan, like a sidewalk or a setback.

3. People who seriously oppose bike lanes are a minority, and those people are cranks. Cranks are everywhere. You have to deal with them, but you shouldn’t make them the centerpiece of what you think about when you think about your job. The average conservative does not worry about bike lanes. Real opposition comes from people who are worried about the other stuff that come with redevelopment (like gentrification and strangers), or because they are worried their ideas and preferences are getting shoved aside in favor of what planners want, or because bike lanes are often packaged with a heart-stoppingly expensive rail project. There are things we can do about the opposition, but it’s not to scream louder about bike lanes.

4. I do think that bike lane babble displaces a lot of the discussion around what other things people really want and need from urban redevelopment, such as ensuring affordability. I think far too many people dance on the head of a pin when it comes to the hard questions of “what to do” in favor of focussing on street amenities because because, as I said, those are a no brainer. Bike lanes are to planners what “our children are our future” is to politicians. If one of the charges is that your profession is marginal and ineffectual, then one of the ways to refute that charge is to pick an inexpensive solution to implement and credit it with having huge, world-altering impacts. I don’t buy this line of professional self-promotion, and I doubt many people outside the profession do, either. Again, I don’t think bikes save the world, but I’m sure that bikes are good for people and neighborhoods. I don’t think we should give up on the big problems in urbanism, or the small ones, either, but I think planning looks foolish when it conflates the two.

5. This does not mean that, if you are a bike and pedestrian planner or advocate, I think your job is trivial or meaningless. Some of the most meaningful things are details and no-brainers. Nobody loves the sanitation workers until they go on strike. Nobody ever thinks about storm drains until they don’t work. Underneath all that public ignorance is a system that works well, in the US at least, because talented and smart people have worked on them, and there are still many problems to solve in those systems. Yeah, surgeons are awesome but so are the nurses who help you go to bathroom. Bike and pedestrian planning matters in the same way, and there is great possibility for doing good and creatively solving problems within the context of bike planning. The political difficulties are real, but planners spend far too much time shadowboxing about the importance of things that are not really controversial with anybody other than cranks (see above). Providing the bread-and-butter in a profession is not as gratifying as it should ideally be if you what you want is wealth and status.

So yeah, bikes lanes? Get ’em done and get busy on the other issues. Of course, if you have framed the world of the city entirely in terms of your pet bike issue, you will be furious with my comments because everything you see wrong with cities is a bike-related problem. My advice is to ask yourself why there was no bike-lane-themed season for The Wire. Perhaps it was a GM conspiracy.

USC’s SHOUT-Y BIKE LANES: Bikers “win”, our community loses

Lisa Schweitzer

Attention notice: Sustainability advocates can be as bad as developers who want to plant megaprojects all over. Strong-arming control over urban space sucks no matter who does it.

My beloved USC has a pretty gnarly bike design problem on its two major thoroughfares. I was rather unsympathetic when my bicycle advocate students went into a fury about USC’s supposed bike ban, which actually consisted of restricting bikes from the major thoroughfares only about 7 hours a day. That left plenty of other walkways for students to use if they wanted to stay on bikes without dismounting.

Now, there are problems with that, too. The rest of the walkways on campus have smaller pavement widths. These major thoroughfares are also dead flat. They are easier to bike on, and the flatness lends longer sight distances that can help pedestrians and cyclists see each other.

Of course, this bike ban was intolerable to bike advocates, who see bike lanes as crucial to their mobility. Frankly, though, there is much of the USC bike advocacy that isn’t about mobility at all. It’s about bicycling advocates feeling like they have visual symbols of their social importance that are stamped on campus and roadways.

So I guess–I guess–there are now bike-only lanes on these major thoroughfares. I found this out today not because there were helpful bike advocate volunteers out working to help explain the new set-up and how people on campus can navigate the new facilities, but by getting screamed at.

I was pottering along dreamily, walking along, when one of USC’s ubiquitous rent-a-cops on a segue started barking at me to move to the side, complete with pompous-looking gestures. I simply thought he wanted through. So I moved to the grass–where, by the way, people sit and walk all the time–and Barney Fife yells at me to get off the grass.

“PEDESTRIANS ON THE OUTSIDE LANE.” He screamed at me as he whizzed by in all his wanktastic glory. I shot back that he should blow it out his ass.

Now, would it have killed him to alight his little scooter to chat with me about the changes and the plans? I get that security people like to project authority, but dude–you are wearing little postal worker shorts and driving a scooter. There’s only so impressed anybody is going to be by you to begin with.

I walk on, my mood destroyed by being verbally attacked at my workplace, and I see another rent-a-cop yelling at a young woman who was *walking her bike* in the ENTIRELY UNMARKED area in front of Tommy Trojan. Yes, these genius new bike lanes just disappear when you get to the campus’s biggest intersection. What was the girl supposed to do? Levitate? When she reached the end of the VERY VERY SPECIAL SEPARATE BIKE WAY, was she supposed to wink into a parallel universe or maybe a wormhole that takes her to the other side of the intersection via Bajor? WTH? She was doing exactly what she should have been doing to be polite, safe, and considerate of others. AND YET CAMPUS POLICE SHOUTS AT HER?

What are we DOING?

Ah, the restful civility that bike planning and campus sustainability brings to a beautiful, sustainable world.

And that’s my point. Hey, the bike advocates “got theirs.” Nothing else in planning matters, right? Culture doesn’t matter, community doesn’t matter, helping people with the transition doesn’t matter. All that matters is your win for the bike lanes. You got your pet project approved and/or built. Good job.

After all, bikers are savingtheplanetandfightingobesityandcleaningtheairandcombattingclimatechangeblahblahblahblahblah and…well, when you are on an important mission like that, making people welcome to use the space now that you’ve got yours doesn’t matter.

No, we aren’t going to train rent-a-cops to stop, get off their little scooters, and actually talk to people like me like we matter in this place. We aren’t going to have rent-a-cops on foot walking around and helping people understand the new, unbelievably crappy signage. No. We are going to shout at people on our campus like they are shoplifters trying to sneak out of the bookstore with Trojan gear shoved under their blouses.

Finally, the design and placement of the new ‘bike only’ lanes makes no sense in an American context, and their placement increases bike-pedestrian conflicts. The bike lanes are on the inside lane, so that NO MATTER WHICH way a bicyclist turns, he’s moving across the “pedestrian way.” By all means, let’s have the heaviest and fastest-moving vehicle have to demonstrate the most care.

Whatever.

Don’t scream if you meet a cow and other rules for women cycling in 1895

Lisa Schweitzer

Mobility is, at its most basic levels, inherently transgressive. If it isn’t, ask yourself why repressive places bind feet, refuse to allow licenses, or even movement outside without complete covering.

Wheels of Changes by Sue Macy has been getting its fair amount of attention around the inter webs, and deservedly so. It’s a delight.

Brain Pickings offers us this list of do’s and don’t for female bicyclists in 1895. It gives us some insight as to all the rannygazoo women were getting up to riding their bikes around cities, including the admonition that one not scream if one meets a cow or discuss one’s bloomers.

Next thing you know, these gals will want the vote.

And I’ll boast of my long rides if I damn well want to!

What if Biking Being a Fun Thing *is* the Important Thing?

Lisa Schweitzer

So how dare I suggest that it might be more important to be a fun thing than an Important Thing?

Let’s look at the other example I give: Locavore food practices are entirely discredited in one regard–they do diddly to reduce transportation-related emissions. They may even add emissions during their product lifeline.

Nonetheless, locavores are still out, doing what they are doing, and with very little opposition. And that may be a good thing. Why? Because local food tastes good. There is a market for it. Having access to it is an amenity–that’s why it’s associated with well-to-do people. Well-to-do people: if we have a particular talent, it’s that we know how to get nice stuff for ourselves.

As a by-product of that, there are perhaps some subsidiary social benefits: people may eat some more veggies, and the food supply in places with few other options can get more and better food. There is a competitor to Big Food Corps. But all those social benefits come first and foremost because the thing–the center idea being sold–has inherent, lasting utility to the people practicing it–including those who aren’t sold on the Grand Social Vision.

So for bicyclists, what does that mean? It means that as soon as you start arguing we should invest in biking because of the Big, Important Social Claims–fighting obesity, battling climate change, the whole ball of wax—that means people are going to start questioning you and challenging you based on the Big Social Claims.

Then pointy-headed social sciences types like me will study it. Half the studies will say Big Important Social Claims are true, and the other half will show little effect. Or worse, like the locavore food studies, the results of the body of research will fail to provide evidence the Big Social Claims really work out.

But biking is still fun at the end of it all. It is indisputably fun. Bikers indisputably derive value from their biking. When was the last time you heard the argument go like this:

You: “Biking is great, I really enjoy my commute.”
Opponent: “No, you’re wrong, you don’t enjoy it.”

Never, that’s when. Your and others’ enjoyment is–after all of the noise–the core value that can not be discredited.

It may be the fault of the public policy field itself, this tendency to want to prove or disprove social good. Or it could be the political discourse we have that acts towards any and all public investment like a Puritan elder rebuking sin: if we want to invest in something, we have to act like Everybody Wins.

But what if it’s entirely legitimate to want your cities to have enjoyable things in them?

Gasp!

And if you think that Being a Fun Thing isn’t more important politically than Being an Important Thing, look at stadiums. There is nothing more settled in the policy research than stadiums. Cities always put more money in than they get out. Perhaps there are a few examples somewhere, but in general, stadiums cost taxpayers money. And yes, stadiums get built because powerful coalitions of elite actors want them. But democratic action matters; if taxpayers really hated stadiums, they’d hand those elites their fannies. There’s a reason why we’ve had decade after decade of stadiums and value pricing on freeways (despite being invented decades ago) is just peeking through the public policy clouds.

That reason: a large subset of taxpayers likes to go to football games and concerts, and large subset of taxpayers hates paying for roads.

Remember when biking used to be a fun thing rather than An Important Thing?

Lisa Schweitzer15 Comments

I think one of the reasons why there is a resistance to otherwise nice things like local foods and bicycling concerns the often terminally joyless way their advocates present the Great Social Good that The Better People Who Do These Things create, unlike you, you indolent, planet-killing dolt.

Before it became about Changing the World and Proper Urbanism and Saving the Planet and Fighting Obesity and Duking it Out With Those Planet-Killing Killers in Cars, Yelling at Everybody to Make Bike Lanes and Treating Bicyclists With the Respect They Deserve, riding a bike outside was…fun.

There’s part of me that thinks the fun part of it is a lot more worthy of public investment than many of the Important Social Claims.

Here are some kids messing around on bikes, no bike lanes, no Proper Urbanism, no multi-million-dollar bike parking facilities with lockers. Just bikes, a makeshift ramp, and some kids with free time (on a low-volume suburban street, for you sensitive viewers who will be scarred at the sight of the hopeless desperation in which these children of the Provo suburbs live, in single-family houses, rather than on the lively, sun-loving, Proper Mixed Use Streets of Much Righteousness). They don’t appear to have sidewalks.

The song is one of my favorites about bicycling, from a band called All The Apparatus.

I like how the kid with glasses mans up at the end. Well done, kid.

Wish they were wearing helmets though.

Bicyclists’ liability

Lisa Schweitzer3 Comments

Bicyclists are fond of telling me that they should be taken seriously as a mode. I do take the mode seriously. But being taken seriously has a double-edge to it.

One of my wonderful PhD students sent this to me yesterday: Cyclist fractures pedestrian’s skull, gets $400 fine

So what is the right response? I suspect that the reason the fine is so light is that the jurisdiction has, in the past, the most experience with child bicyclists, who do little damage (usually hurting themselves, unfortunately). But this was 49 year old man behaving like an ass.