Helmets: Are bad stats leading to bad bills?

California state senator Carol Liu introduced an all-ages bicycle helmet bill yesterday, much to the dismay of many people who know a thing or two about helmet legislation. The early betting has the bill dying quickly in committee or elsewhere, although in a sense it might be productive to have a full and lively hearing about the merits of bicycle helmets. Some of the dismal, even disastrous, examples from places like Australia and New Zealand — where helmet legislation has apparently had no safety effect while also reducing cycling significantly — might kill these ideas for years to come.

Senator Liu’s press release included this statistical “gem” taken from a report by the National Conference of State Legislatures (NCSL): “Ninety-one percent of bicyclists killed in 2009 reportedly were not wearing helmets.” Since she mentioned it, Senator Liu is apparently relying in some part on this number to make her case. Where does it come from? Does it hold up to scrutiny? Does it reflect the California experience?

The underlying NCSL report doesn’t mention sources, but it’s a pretty safe bet that its numbers are coming from FARS, the federal Fatality Analysis Reporting System. FARS, in turn, gets its data directly from state highway data collection systems, which are implemented at the local law enforcement level. In California, the Statewide Integrated Traffic Records System (SWITRS) plays that role, and its data is open to all comers — including me, as it happens.

Over the past few weeks, I’ve been toying with SWITRS data, trying to understand its structure, and looking into what it might reveal about our roads. I’ve only gotten my feet wet with it so far, and I’ve much to learn, but from what I’ve seen, Liu’s “ninety-one percent” number is problematic. Take the year 2009, the year she singles out for mention. FARS shows 628 total cyclists killed in the U.S. that year. SWITRS tells me that 107 California cyclists were killed in the same year; presumably, those 107 are included in the 628 total. How many of those killed California cyclists were wearing helmets? SWITRS tells me there were twenty-two cyclists wearing helmets, sixty-seven who weren’t, and eighteen unknowns. In other words, in California sixty-three percent didn’t wear helmets — not ninety-one percent, as the nationwide number suggests — twenty-one percent wore them, and for seventeen percent of cycling fatalities we have no data.

My point might be small, but it should be in the mix nonetheless: Senator Liu implies that only eight percent of killed cyclists are wearing helmets, but in California that’s just not the case. More than double the cyclists are wearing them, and even more might be, if we knew more about those many unknowns. The hard facts? Lots of Californian cyclists are being killed despite their helmets, just as other studies show. We need to spend time confronting the real factors, like bad road design, high speed limits, and poor cycling infrastructure if we expect to make a real dent in fatalities.

Where does FARS get that huge ninety-one percent number? I’m not sure yet, but it sure looks suspiciously like they are grouping the unknowns in with the nos. That is a big no-no!

Just for completeness, I went back and extracted the numbers for all the years for which we have full SWITRS data (2001-2012):

Year	No Helmet	Helmet	Unknown			No helmet	Helmet	Unknown
2001	76	17	23	116		66%	15%	20%
2002	78	22	15	115		68%	19%	13%
2003	81	27	18	126		64%	21%	14%
2004	74	27	22	123		60%	22%	18%
2005	75	20	37	132		57%	15%	28%
2006	100	34	21	155		65%	22%	14%
2007	76	25	23	124		61%	20%	19%
2008	73	30	27	130		56%	23%	21%
2009	67	22	18	107		63%	21%	17%
2010	67	24	20	111		60%	22%	18%
2011	81	33	26	140		58%	24%	19%
2012	77	49	20	146		53%	34%	14%

As far as I can see, never in the past twelve years of data has any year approached Senator Liu’s number. Whatever comes of Senator Liu’s legistration, we should make sure that incomplete data don’t lead to bad statistics used to justify bad policy enshrined in unhelpful laws.

One of These Things is Not Like The Other

In his book, Intelligence and How to Get It, Richard E. Nisbett asked Easterners and Westerners to group the words chicken, cow, and grass. The Americans tended to put chickens and cows together, “because they are both animals; that is, they belong to the same taxonomic category.” The Asians, by contrast, “focusing on relationships, were more likely to say that cow goes with grass because a cow eats grass.”

How would you group these three words: pedestrian, bicycle, and car?

It’s not just an academic exercise, because the way we categorize these three transportation modes determines in large part how we think about their place on our roads and in our law — and by extension, how we think about safety measures. If we say that the bicycle and car go together because they are both machines, then we might tend to ask cyclists to mix it up with cars, and talk about licensing, insurance, etc., in the same way we talk about cars. If, instead, we say the bicycle and the pedestrian go together because they are both human powered, then we might tend to think very differently about how we allow them to operate, including making safer environments and writing laws that address their particular needs.

In a compelling talk at the London School of Economics last month (h/t to Amsterdamize), Enrique Peñalosa, the former mayor of Bogotá, called the bicycle an “efficient way of walking.” He seems to think bicycles are more like pedestrians. Meanwhile, in New York City, the police have cracked down on red-light running cyclists, including those who make a right turn on red, illegal in Manhattan. Sticklers for the law might protest, but it does seem somewhat stupid that NYC allows walking a bicycle around a corner on red but not pedaling it.

What do you think? Are bicycles more like cars or more like pedestrians?

Beverly Hills Bicycle Licensing

Santa Monica’s repeal of its bicycle licensing ordinance last night prompted me to look at the rules for Beverly Hills, where I live. As it turns out — and much to my surprise — we still have a licensing provision on the books from 1962, under Title 5, Chapter 5: BICYCLES:

It shall be unlawful for any person to operate or use a bicycle, as defined in section 39000 of the Vehicle Code of the state, upon any street, public path or way, or other public property in the city unless such bicycle is licensed in accordance with the provisions of this chapter. (1962 Code § 3-1.01 et seq.)

I called City Hall in hopes of finding out how I would go about getting a license. The City Clerk’s office forwarded me to the Police Department’s Watch Commander … who forwarded me to the Traffic department … who put me on hold to call the Finance department … who told Traffic to tell me that Beverly Hills no longer issues bicycle licenses. Whew.

Then I called the (only?) local bike shop, Beverly Hills Bike Shop, to see whether they knew anything about the ordinance. They should know about it, because it also requires them to “file a report with the director of finance administration of all new or used bicycles purchased or sold with the identification of the purchaser or seller within ten (10) days of such transaction.” The guy who answered the phone said the licensing law wasn’t enforced, although it used to be.

The ordinance also has a rather substantial rewording of the California Motor Vehicle Code Section 21202(a). The Beverly Hills Municipal Code states:

The operator of a bicycle shall operate such bicycle as near the curb as possible on any public street or highway.

By contrast, California code states:

Any person operating a bicycle upon a roadway at a speed less than the normal speed of traffic moving in the same direction at that time shall ride as close as practicable to the right-hand curb or edge of the roadway …

The difference between “as close as practicable” and “as near as possible” has spawned much discussion on the interwebs. The State statute is usually taken to mean that riders can “take the lane” and ride well out into the street, when circumstances dictate. The other formulation doesn’t have the same flexibility at all. I would argue, however, that the State statute overrides Beverly Hills’ ordinance, and renders the city ordinance a rather useless bit of law.

Of course, the city ought to remove these laws from its books, as they provide too much opportunity for a “rogue” officer to enforce them selectively. Contact the city council!

The Social Cost

In my memory, he was a reed-thin, almost delicate man, with curly hair and a slightly exasperated demeanor. He was obviously intelligent, and his lectures in my philosophy of law class were always rich in detail and balance. He tackled the big subjects — the death penalty, for instance — with the same even-handedness as others, always probing, always neutral. I was a little surprised when he revealed his love for motorcycle riding, and even more surprised when he expressed such disdain for California’s mandatory motorcycle helmet legislation, which was then on the books but not yet in effect. His opinion still sticks with me today: “I would rather not ride,” he said, “than ride with a helmet.” I’m a little sorry that I didn’t keep up with him after I left school; I don’t know whether he quit riding the following year or two when motorcycle helmets became obligatory for everyone. What I do still find interesting, though, is that the same arguments we tackled then in class over motorcycle helmets are now, nearly twenty years later, being broached yet again, this time in a huge war of words over bicycle helmets.

Elly Blue’s recent Grist article on bicycle helmets sets out the major combatants, with some particular focus on Copenhagenize.com‘s Mikael Colville-Andersen, calling him “the face of the anti-helmet movement.” I’m not sure that this designation is entirely accurate, for it ignores his many antecedents and philosophical compatriots. It also puts him in the uncomfortable position of being an “expert” on bicycle helmets, a moniker that he probably doesn’t want or deserve. Imagine the decision matrix of alien, asked to make a choice about helmet wearing, with the only inputs being these two TEDx videos about helmets, posted only a few days apart:

If I were that alien, presumably a bit risk averse and self-preservationist, I’d probably err on the side of caution, and go with Dr. Gergens’ advice to wear a helmet, even if she seems a bit smarmy and overbearing. She’s an expert on the brain; he’s a photographer who takes many photos of well-dressed women riding bicycles. Her qualifications go far beyond Colville-Andersen’s I-read-a-few-papers “research” résumé.

Any discussion over helmets really comes down to two questions, both related but with different arguments underpinning them:

► Should I, as an individual, wear a helmet?

► Should we, as a public policy matter, make helmet wearing mandatory?

These are yes-no questions, and their possible answers are straightforward:

Personal Choice	Public Policy
I wear a helmet	I want mandatory legislation
I don’t wear a helmet	I don’t want mandatory legislation

The American cyclists I’ve met and read tend to have the ideological viewpoint represented in red: they (mostly) wear helmets while riding but think mandatory legislation isn’t necessary. I share the same viewpoint. I wear a helmet because I feel safer. This is my choice. But the broader issue of whether we ought to require everyone to wear them requires a far different calculus. Public policy is not about personal decisions writ large, but about the (too often negative) impact of collective decisions writ small.

Part of the problem may be that it’s difficult to tease apart motorcycle helmet arguments from bicycle helmet arguments. It’s tempting, of course, to equate the two, given that they both involve two-wheeled machines and both involve helmets, but there are real and substantial differences in their application. For those who haven’t seen them, the best anti-and-pro mandatory motorcycle helmet arguments can perhaps be summarized in two lines:

► Anti: The state has no compelling interest in making helmets mandatory because the decision to wear them or not affects no one else.

versus

► Pro: The state has a compelling interest in mandating helmets because the “collective social costs” (direct medical, reduced productivity, emotional distress) to the society are higher when unhelmeted motorcyclists get into crashes.

Given the U.S. Constitutional principle of substantive due process of law, which requires (among other goals) that legislation be “narrowly targeted” at a “compelling” state interest, the cost argument has done all or most of the work of finding a state interest. Without that, it becomes more difficult to show why the state has any interest in interfering in the private choices of individuals (the anti argument), even if you happen to think helmet-wearing is generally a good idea. It’s probably a good idea to wear shoes while walking on concrete, too, but passing a law to mandate shoe-wearing probably doesn’t make sense.

Whatever its shortcomings, the cost argument probably applies to the bicycle helmet debate exactly opposite to the way it is generally applied to motorcycle helmets; that is, requiring bicycle helmets has a higher social cost than not requiring them. If we accept that there are large societal benefits to cycling — which seems to be universally acknowledged even by people temperamentally skeptical of cycling — this conclusion depends almost entirely on the large question of whether mandatory helmet legislation tends to reduce ridership. The studies on this point are inconclusive, but generally tilt towards answering yes.

Studies aside, helmets must have a negative impact on cycling for the simple reason that they complicate the decision to ride. Helmets have to be purchased, carried, and worn. They are non-integral to the act of cycling, unlike, say, the way an arrow is integral to the act of archery. If they’re lost, they have to be replaced. I could go on…

In the motorcycle domain, there was a collective shrug over the (possible) departure of helmet-hating riders. The government didn’t really care whether we had fewer motorcycles on the road. The public good wasn’t enhanced or diminished by their absence. Motorcycles may reduce congestion, but by some metrics, they can increase (!) pollution, and they do nothing for public health. By contrast, the benefits of cycling mean that reduced ridership would have a negative cost.

Fortunately, at the moment I don’t know of any serious proposals to make helmets mandatory, at least not in California. Los Angeles mayor Antonio Villaraigosa found himself booed when he mentioned such a proposal earlier this year. Maybe that reaction, and more like it, will keep it off the agenda for now … and for good.

Burden of Proof

In translation, Article 185 of the Dutch Road Traffic Act seems to hold drivers “strictly liable” in crashes with vulnerable road users like pedestrians and cyclists. Hans Voerknecht’s layperson description of its relatively heavy consequences to drivers has created small tremors in the American bicycle-and-pedestrian blogosphere. With so many traffic incidents resulting from careless drivers, one might wonder whether strict liability might not incentivize better driving behavior, especially behavior directed towards vulnerable road users.

Article 185 does seem to come very close to the American concept of “liability without fault,” which may be the simplest definition of strict liability. While I don’t speak Dutch, what little I’ve been able to gather about the law corresponds well to Voerknecht’s basic outlines: drivers of motor vehicles on the road are strictly liable to vulnerable users outside their car (but not passengers). If drivers can show contributory negligence, their liability may be mitigated, although they will always be at least fifty percent liable, and in cases involving children under fourteen, they are always one-hundred percent liable. Drivers can escape liability only by showing force majeure; for instance, someone else was driving the car, or the injured person was trying to commit suicide. In one case I found, a moped rider escaped liability for killing a drunken man who had fallen asleep on an unlit road, at night, and could not be seen under the circumstances. By contrast, a Dutch friend of mine found himself having to pay for damages to a young cyclist even though every witness he had agreed that the crash was the boy’s fault.

I think it’s difficult to understand the role of Article 185 without at least a nod to Netherland’s tort law, its social welfare system, and its auto insurance requirements. This backdrop may create a more favorable environment for legislators to place a higher degree of responsibility on drivers, especially by comparison to our own, sometimes skewed system. For example, recoveries for injuries seem to be downright modest by comparison to some awards in the U.S. According to one paper I located, the “loss of one leg, below knee” will usually mean an award of 15,000 to 20,000 euros, far less than, say, the Los Angeles attorney who successfully sued for $4.5 million for “a switchman who lost his leg below the knee.” Similarly, Holland’s mandatory and highly regulated medical insurance coverage means that injury costs may often be covered by health insurance, with no further look towards negligent drivers. Too, my Dutch friends tell me that auto insurance in Holland is issued for cars and goes on the registration record of the car. As such, I would expect that car insurance compliance is higher than in the States, where insurance is for drivers (not cars), and only checked after a crash or in the rare instances that police pull over drivers. Each of these elements allows legislators to tilt the playing field towards vulnerable users without creating a political maelstrom.

In American jurisprudence, liability without fault has long held an uncomfortable position. Our laws and court opinions rarely extend strict liability in a civil context, and the few instances we have are riddled with seeming inconsistencies. California statute will hold you strictly liable if your dog bites the neighbors, but not when your cat rips their couch to shreds. Our courts have developed strict liability theories for product manufacturers and “abnormally dangerous activities,” but have carved out many exceptions. You may find it ironic that driving is not considered an abnormally dangerous activity, given the widespread carnage autos wreak on our roads, but it falls under a “common usage” exception. Activities aren’t abnormally dangerous if everyone is doing them.

(I think it’s not too hard to imagine a different opinion about the car’s danger if it were introduced today.)

I have few hopes of California legislators suddenly passing a Dutch-style strict liability law. While you can make a very good argument that drivers should have high levels of responsibility for their conduct, and owe a substantial duty of care towards vulnerable road users, you’d have to make those arguments in context of our broader legal, health care, and road system. Vulnerable road users often suffer more than the drivers who injure them, but our legal system generally puts liability in some relation to fault, and not merely to the gravity of injury. It’s a morally questionable position to hold people completely liable for a crash no fault of their own, especially when the financial and familial consequences can be catastrophic.

But still.

Cyclists have named whole categories of driver excuses based on their commonality: the SMIDSY (“sorry, mate, I didn’t see you”) and the SWiSS (“single witness suicide serve”) are two I know; there may be others. The near-insouciant means with which these excuses are employed sometimes stagger my faith in the basic goodness of humanity. They are the punch lines to the old joke that driving is the easiest way to get away with murder. They also point up a basic problem of determining fault in collisions with cyclists and pedestrians: vulnerable users are often rendered incapable of being effective witnesses, and the tell-tale signs that wrecked cars leave (skid marks, crash damage location) are sometimes confusing or absent altogether.

Our traffic systems, our infrastructure, our laws, and our law enforcement are all set up for cars. I don’t think any of these systems is necessarily “against” cyclists and pedestrians, but their implementation has the side-effect of disadvantaging them. When it comes to fault determination, they put vulnerable users in the extraordinary position of having to do more to show fault than drivers do. Short of a Dutch-style strict liability law, what we need is some mechanism to level that field, to shift the difficulty of showing fault away from the cyclist or pedestrian.

Here’s a simple proposal: in any crash involving a driver and vulnerable road user, the burden of proof of innocence or fault is placed on the driver; that is, drivers are presumed to be at fault unless they can show otherwise. In the SWiSS cases, for instance, drivers would have to do more than allege the cyclist darted in front of them, they’d have to prove it. The SMIDSY cases would require the same.

A “rebuttable presumption of fault” wouldn’t be perfect, but it would be a start. And maybe that’s all I can ask … for now.