Archive for the ‘Risk’ Category

The conclusion of the study is that being a Catholic country or not seems to be as important as being a wealthy country or not. Being a non-wealthy Catholic country leads to more traffic and hence more motor vehicle accident deaths than being a wealthy Catholic country. Being a wealthy Catholic country, however, does seem to lead to more previous traffic term accidents than being a wealthy non-Catholic country.

That’s from: K. Melinder, “Socio-cultural characteristics of high versus low risk societies regarding road traffic safety,” (2007) Safety Science, 45 (3), pp. 397-414.

From an interesting post at CSV, via Marginal Revolution:

This phenomenon, where improved safety spurs on greater risk taking, is known as risk compensation, or “risk homeostasis”. Most of us became familiar with the concept from debates over anti-lock brakes (ABS), but its specter has plagued nearly every attempt to improve automotive safety, from seat belts to night vision. Yet almost nothing about risk compensation - its etiology, its prevalence, its significance - is certain.

To prove the phenomenon even exists, one particularly inspired British researcher had volunteers ride bicycles on a closed course, with half the people wearing helmets and proper attire, and the other half clad in their underwear. Graduate students positioned on the sidelines graded the volunteers performance and tallied any unsafe maneuvers. The results showed that the unclothed group practiced much safer driving habits, thereby supporting risk compensation theory - and Britain’s reputation for eccentricity.”

The first thing that jumps out in this piece is the identification of the victim as “homeless.” A subtle detail, or some kind of implied pejorative — hmm, maybe he was one of those crazy guys you see wandering willy-nilly across the street, and perhaps he was asking for it. Can you imagine the headline: McMansion Owner Struck and Killed by Car in Santa Barbara?

The victim had already been struck by a car before — the driver was cited with failure to yield — but the circumstances here beggar belief:

Castillo, according to McCaffrey, told investigators that he thought the man would clear the intersection before he drove through, but wound up striking the victim with the right front of his car. The victim was reportedly swept up onto the hood of the vehicle before falling to the pavement.

Yes, it’s always a good idea, when approaching an elderly pedestrian, to continue at speed in a multi-ton vehicle towards someone crossing in a crosswalk, owing to your own faith in your driving abilities and your estimation of their walking speed. There’s certainly nothing that can go wrong there, unless, oops, you have an “accident.”

Random fact of the day, via the WSJ:

State Farm, the nation’s largest insurance company, says that currently its auto coverage premiums for teenage boys are about 40% higher than for girls. In 1985, that gap was about 61%, says Vicki Harper, a spokeswoman for State Farm, which has more than 42 million auto policies. Most girls still get a break on premiums, she says, but “their premium rates reflect there isn’t as much of a difference as the rate for a teenage boy.”

If you want to know why pedestrian fatalities dominate the global traffic safety picture, this CNN clip from Cairo is one of just many places you could start. And please, Cairo, don’t make the mistake of building pedestrian overpasses and underpasses to “fix” the problem.

(thanks vagabond)

Via Nudge, a fascinating article about trying to prevent railway crossing deaths (by pedestrians) using a variety of behavioral cues intended to counter perceptual biases and guide decision-making:

From all this research, Shroff identified three major decision-making principles in operation on the Wadala tracks. “One is a combination of the Leibowitz Hypothesis and the Looming Effect. Large objects appear to move slower than small objects, and people can’t judge their speed,” she says. “Another is the Cocktail Party Effect: The brain isn’t wired to follow two conversations, or do two activities simultaneously. If there are two trains on adjacent tracks, you’ll register one, but not the other.” The third is simply a flight response—a tendency to run, which minimizes good judgement.

At the station itself, Krishnamurthy points to the final intervention—a three-panel photo of a rather alarmed man being gradually run over by a locomotive. This morbid frieze is positioned exactly at the two points where the temptation to cross is powerful, designed to subtly counter the flight response.
“It’s intended to elicit an appropriate emotional memory,” Krishnamurthy says. “We look to faces to figure out situations, so his face is central. We repeated the image, because it catches the eye. And it has to be life-size, not larger than life, because it shouldn’t intrude into the conscious. It should work at an unconscious level.”

I’m slow to get to this, but this incredible case of a sideways high-speed shunt in the U.K. is about as dramatic a case you can imagine of how divorced a motorist can be from the world around him.

Via the BBC:

In a bid to release her vehicle, she said she pulled on the handbrake and flashed her hazard lights to try to catch the driver’s attention, as well as that of other road users, but she said it took the lorry driver nearly a minute to notice her.

When he did he was “all over the place”, Mrs Williams said, and finally managed to bring both vehicles to a stop on the hard shoulder.

Reading, via Tyler Cowen, about this controversial classical music behavioral nudge in the U.K. — act badly and you’ll get blasted with Brahms — put me in mind of a way to make things safer for teens (and everyone else) on the road. Since BPMs often seemed tied to RPMs when teens are at the wheel, how about using the car’s increasing electronic integration to hijack the stereo when aggressive driving is detected, pumping in some Sibelius or Chopin to attenuate the raging hormones? (one wonders more broadly about some kind of iTunes ‘genius’ system that measured surrounding traffic density, car speed, etc., and used it tailor musical selections — Satie for that frenetic rush hour scramble at the Holland Tunnel, Brian Eno for those epic tunnels in Norway (ok, wait that’s a bad idea), rousing anthems (e.g., the Pogues) for long, dark quiet roads.

Which reminds me of one last point: The curious power (both as narrative and sense-memory) a song can have in the context of a drive. I once almost drove off the road in rural Maine at night when I first heard the plaintive, haunting voice of Townes van Zandt singing Kathleen:

It’s plain to see, the sun won’t shine today
But I ain’t in the mood for sunshine anyway
Maybe I’ll go insane
I got to stop the pain
Or maybe I’ll go down to see Kathleen.

When I hear that song today I still recall a glowing white line, the dark outlines of tall trees lining the road, glittering moose eyes…

Richard Stampfle writes:

This is a true picture of a bus in Thailand used to deliver school children to functions. It is representative of many vehicles in Thailand, it is not an exception. I have hundreds more photos I could have used. While we may recognize that the driver cannot see you will find it strange to learn that most Thais find no problem with this picture. I have asked several what is wrong with the picture; one commented that it should be Liverpool not Manchester United on the Glass. One felt the colors were somewhat gaudy but that is a matter of taste. No one commented on the safety issue. When I showed a similar picture at a meeting of the Thailand Global Road Safety Partnership the only suggestion was that I should do some research on the subject and gather sufficient statistics to get the attention of law makers — if indeed this was actually a problem. (There seemed to be some doubt.)

The Daily News notes that a number of trees are going to be cut down on Pelham Parkway in the Bronx and replaced by a guard-rail, presumably to cut down on the number of fatalities by drivers swerving into trees. “The roadway is very dangerous the way it is,” a local pol said.

But dangerous for whom? As the story notes:

According to Police Department figures, there were 185 accidents — with 29 injuries — from January to July 31 of this year along the parkway. Since 2003, there have been two fatalities, both involving struck pedestrians.

The only certainty in removing trees is that speeds will increase. I’m not sure how those pedestrians were struck, but I would guess the issue is not that the trees failed to protect them, and their risk will only increase with driver speed.

(thanks Streetsblog)

A few kind readers have sent along an op-ed in the Boston Globe, which the website sums up thusly:

“Traffic injuries kill more than a million people a year worldwide, including 40,000 a year in the United States. Yet when a fatality occurs few people blame the roadway for the death.”

The piece makes some good, worthy points (and it’s important to remember that the concept of safer road design can also entail — gasp — forcing drivers to slow). It’s a bit like the concept of “fire-safe cigarettes.” We can try to educate people not to smoke in bed, we can fine them if they do; or we can build a device that extinguishes itself, lowering the potential for a human mistake.

But it also reminded me of a story in today’s New York Times about the deadly crash on the Taconic Parkway (in which the driver was subsequently reported to have a BAC twice the legal limit; before this, there was a grasping search to blame improper road design or poor signage). The story tries to insinuate that the parkway, designed in the 1920s, is no longer safe — the reason, of course, having less to do with the road itself than that drivers no longer feel compelled to drive the 55 mph speed limit (partially because it became a conduit for a sprawl-based commuter-shed). Curiously, though, the piece notes that the Taconic turns out to be safer than comparison roads, thereby somewhat deflating the sense of urgency that this is a road in need of serious examination.

And yet, after the crash, officials put up additional “wrong way” signs at the particular intersection where the driver joined the highway. A natural response, perhaps, but one done more out of reflex (the “accident black spot” approach) than thought: What about all the other entrances? Given that the driver drove for several minutes, clearly against the flow of traffic, what would another ‘wrong way’ sign have done? The point here is that road engineering can only get us so far in reducing deaths; driver behavior matters.

According to the UC Berkeley Traffic Safety Center, more than 80 percent of crosswalk collisions are related to driver behavior – not pedestrian behavior.

From a salutary editorial in the Sacramento Bee.

I’m currently in Texas, and just heard an item on the radio about a curious new law: That it’s illegal to use a (hand-held) cell phone in a “school zone.”

And, as an article by Ben Wear (who was on my panel back at the Texas Book Festival last year) in the Statesman notes, cities like Austin now have to (or don’t, it’s still a bit up in the air) post signs alerting drivers to the presence of this law, otherwise police cannot enforce.

Robert Spillar, the City of Austin’s transportation director, said the city has not set aside money for the signs. Nonetheless, it will begin installing them this fall, starting with elementary schools. It could take two years to get them all up, he said.

“I don’t see how we can not put them up,” Spillar said. He said he isn’t sure the mere presence of signs will change driver behavior, and said some sort of education program might be necessary to get the message across. “It’s an unfunded mandate that has our backs against the wall. We can’t enforce it if the signs aren’t up.”

This is the first I’d heard of such a particular distinction being made in a particular zone, and I’m having trouble seeing the reasoning, or the safety impact. The first thought that jumps to mind is that a driver on a cell-phone is hardly likely to pick out a “no cell-phone” sign, much less expeditiously hang up their call as they approach. The second is that signs warning of “school zones” themselves, while a bit better — particularly when backed up flashing lights — than the ubiquitous (and absolutely ineffectual) “Slow Children” signs that are not officially recognized by engineers, tend to be little regarded as well, at least based on various tests in which drivers were still found to be routinely exceeding the speed limit; typically it’s the parent bringing their kids to the very same school. The entire concept of “School Zones” is a bit wanting, really, prone to driver and legal confusion, not to mention that it raises that eternal question: One is supposed to drive slowly and attentively on this stretch past a school, but it’s then OK to accelerate to higher speed a block later (a block on which there may be just as many children)?

And then, on the cell phone issue, we’re again making odd distinctions: We’re admitting that cell phones are a hazard to use when driving around groups of children at schools, but somehow OK when driving among groups of pedestrians or cyclists or children on the blocks in front of their homes — or in fact every other car on the road? And that it’s OK for drivers to zip past schools while talking on their hands-free-not-brain-free unit?

And then there’s the aesthetic blight of all the extra signage — more signs for drivers to ignore — not to mention all the money going to put the signs up, just so a law can be enforced; it seems rather ridiculous that if a state law is passed declaring it illegal to use cell phones in a school zone, one would have to expensively repeat that statement at every already marked school zone. After all, we don’t feel the need to erect signs announcing that driving while impaired is illegal, in school zones or anywhere else.

As always, any experiences or technical clarifications welcome.

The answer, interestingly, is October. That’s what Michael Sivak concludes in a new paper in Traffic Injury Prevention.

March has the lowest fatality rate (8.8 per billion kilometers), followed by February and April. Thus, the risk of a fatality per distance driven in October is about 16 percent greater than the risk in March.

Sivak notes that the factors for seasonal variation in crash risk are, as one might expect, complex — ranging across everything from alcohol consumption to “duration of darkness” to leisure driving (”Leisure driving, which occurs more frequently on unfamiliar roads, at higher speeds, at night, and under the influence of alcohol, is riskier than commuter driving”) to weather (”Inclement weather (e.g., snow and ice), everything else being equal, should increase the risk of driving. However, because
inclement weather also leads to general reductions in speed, the net effect is not clear.”)

In light of all these, October seems a bit strange; not as much vacation driving as during the summer, inclement weather hasn’t kicked in in most places, though the onset of earlier darkness might be an issue (not to mention the outlier day of Halloween).

I’ve finally gotten around to reading ‘On a Crash Course,’ a report by Ted Miller and Eduard Zaloshnja that’s been getting a lot of play in the media. As the Post summarizes:

Bad highway design and conditions are a factor in more than half the fatal crashes in the United States, contributing to more deaths than speeding, drunken driving or failure to use seat belts, according to Ted R. Miller, who co-wrote the 18-month study released yesterday.

Road-related conditions were a factor in 22,000 fatalities and cost $217.5 billion each year, the study concludes. By comparison, Miller said, similar crashes where alcohol was a factor cost $130 billion, speeding cost $97 billion and failure to wear a seat belt caused losses of $60 billion.

Despite being sponsored by a consortium of road-building concerns, who naturally have a vested interest in highway improvements, there are some interesting and commendable points raised, or at least implied. The first is, given that road crashes bear a larger societal cost than congestion, we should be focusing whatever stimulus dollars (too many, in my opinion) are going to roads on indeed bringing up deficient roadways to modern safety standards, rather than building new roads. Unfortunately, this does not seem to be the case.

Another thing that caught my eye was the high figure of deaths attributed to roadway condition: “Roadway condition is a contributing factor in more than half—52.7 percent—of the nearly 42,000 American deaths resulting from motor vehicle crashes each year and 38 percent of the non-fatal injuries. In terms of crash outcome severity, it is the single most lethal contributing factor—greater than speeding, alcohol or non-use of seat belts.”

This surprised me, as any number of previous studies, including the famous (and much more comprehensive) Indiana Tri-Level Study, as pictured below, paint a different picture of causality.

(more…)

I earlier ruminated on what might happen to traffic fatalities in the midst of the swine flu epidemic (and noted the vast gulf between the numbers of deaths from both causes).

An answer of sorts has come from Mexico City, from Eric Britton over at World Streets. Via the newspaper Reforma, we learn:

Apparently the swine flu in Mexico City caused few real deaths but many traffic deaths. The large drop in the volume of cars increased velocities and also increased traffic fatalities. There were 12 traffic fatalities in the 6 days before the government issued their swine flu alert and 75 traffic fatalities in the 6 days after.

Here is the kicker: the increase in traffic deaths (63) dwarfs the number of swine flu deaths (8) during those six days.

This is hardly scientific, and I’m dubious increased speeds would be the main reason — I’d guess instead higher exposure from people avoiding public transit — but it is certainly suggestive.

Photo by uopfindsomt/Flickr

A few winters ago, I found myself in Copenhagen’s Tivoli Gardens at Christmastime. I was struck by the presence of a number of open-air containers holding little burning piles of coal (or some such), cheerily blazing through the Danish night. What got my attention is that these were in no way marked or restricted. There were no ominous warning signs (Caution: Coals are Hot When Heated!), no barriers, no minders, no consent forms to sign. And surprisingly, there were no mass incinerations of Danes on the spot, no burning children running in terror, no medics on the spot administering salve and bandages (unless I missed that study, “On the Prevalence of Second-Degree Hand Burns at an Unprotected Heat-Emitting Device: A Weighted Exposure Analysis,” in the Royal Danish Journal of Random Minor Public Risks). Just people warming their hands, drinking their glog, and moving on.

Back in the litigious U.S., I am constantly reminded of that moment in Copenhagen. The most recent event to do this was the purchase of a rear-facing infant car seat (yes, some of you predicted there would be infant car seat posts!). Now, this is not necessarily an object one buys for aesthetic reasons, but I was dismayed to find any number of yellow-and-black warning stickers pasted all over its frame (in multiple languages), essentially warning me not to put this rear-facing infant car seat in the front seat. Given that my car doesn’t have the NHTSA-approved “latch” system in the front seat, I’m not quite sure how I’d even do this, but in any case the stickers are almost impossible to remove. Now, this is a device for which one needs to read the instruction manual rather carefully to install (of course, many people do not), so I’m not sure why it also requires a profusion of permanent warning stickers as backup. Maybe I’ll loan my car, car-seat, and infant to someone else? Well, wouldn’t I make pretty darn sure that person knew not to put the car seat in the front seat? Perhaps someone will steal my car and put my infant car seat in the front seat, smash it up, then sue me?

The reason the car seat is not supposed to go in the front seat, of course, is that it would, among other things, run the risk of being impacted by the front passenger airbag. And I know all about this device because of the virtually impossible to remove warning stickers that are plastered to the visor, warning me, in various ways, about having small, unrestrained children in the front seat! Being of sound mind and body, and having absorbed the knowledge about this via the car’s manual (among other sources), I had thought this sticker could be removed (and isn’t there something a bit creepy about a safety device coming with a warning in the first place?), but it stays to this day (apparently there are incredibly labor intensive, and not guaranteed, ways to remove it).

I am all for safety, but do we really, apart for any reason other than a potential lawsuit against a company (and I wonder how many of these been launched against the auto/car-seat makers when the product is used in an inappropriate manner), need these omnipresent warning stickers? Are we saying that we have entrusted someone enough to drive a car in the first place (a process that admittedly has been made too easy in the U.S.), have a child (er, ditto), and then still not possess sufficient intelligence to know how to handle safety devices and infants? Why must I “subsidize” — with these offensive stickers all over my stuff — the foolish acts of others? There are myriad ways to die in a car — mostly having to due with negligent acts by the driver involving the actual act of driving, as well the unlawfully high speeds these machines so easily attain (there’s no warning sticker on the speedometer, mind you) and not seating infants in the front seat. Why don’t we direct some of this attention that way?

Then we can take all these warning stickers, gather them up, and roast them in a big bonfire in Tivoli Gardens — just make sure to sign the release form.

I’ve been interested in the work of UC-Berkeley’s Douglas Cooper and David Ragland on crashes at railway crossings. Looking at incidents that occurred between 2000 and 2004 in the state of California, they found that “of the crashes that occurred, 73 percent occurred at crossings equipped with gates, 59 percent involved vehicles moving over the crossing, and 27 percent involved vehicles that had driven around or through lowered gates. An unbelievable number, 21 percent, involved a vehicle running into a moving train.”

I couldn’t help but think of those findings when I recently came across the following remarkable passage in John Stilgoe’s book Metropolitan Corridor: Railroads and the American Scene, describing the early problem of dealing with vehicular traffic at railroad crossings:

“Adding gates, bells, and electric flashing lights at some crossings at first seemed to help, especially if the gates overlapped each other to prevent motorists from snaking past them onto the tracks. But by 1913, experts knew that numerically as well as comparatively more persons are killed at protected crossings,” at crossings defended by watchmen, gates, bells, lights, and signs. What accounted for “comparatively”? Certainly protected crossings usually passed many more wayfarers than unprotected rural crossings far from towns, but why did proportionately more people collide with trains there? Did carelessness born of some mad scurrying haste account for the deaths, or was it the old “familiarity with the timetable” syndrome? If anything, a sort of early-twentieth-century highway hypnosis might explain the accidents at protected crossings. “How many of you readers heard your clock strike at the most recent hour?” asks Whiting in his 1913 article. People intimately familiar with their route to work, to shopping, to school, simply did not realize the protected crossings. Lost in some sort of waking trance, they walked past the lights or drove directly into and through the gates. “Disgusted railroad men will sometimes tell you that the more you protect a crossing, the worse people behave,” Furnas noted in 1937. “They seem to figure that if the company has taken all that trouble, the drive is absolved of responsibility for himself.” So concerned were California authorities that as early as 1917 they began designing speed bumps into paved highways approaching crossings, hoping that a violent jarring would knock motorists out of their trances and apprise them that they “should cut down speed and be on the lookout for warning signals.” By 1937, after the speed bumps had increased in height to two or three feet, one magazine writer concluded that they did nothing to alert motorists. Drivers simply breezed over them, crashed through gates, and struck trains. When reformers suggested that railroad companies install gates so solid that motorists could not break through them, companies replied that such gates could not be designed. The flimsy gates, they explained, existed to permit motorists to crash through both pairs and escape death, or through the far pair if they entered the crossing as the gates lowered. By the early 1930s, the protected grade crossing displayed the gadgets of mechanical, electrical, and efficiency engineers—and all of the engineers had failed.”

An interesting early example of the challenges of safety engineering in light of human risk compensation, and clearly a longstanding problem that has not been solved.

Yet another driver is implicated in texting while driving — this time a trolley in Boston. Given the trouble that highly trained drivers have with distracting technologies, it doesn’t require much imagination to think what’s happening to the average car driver as they remotely engage.

David Williams of the Telegraph gives a prototype vehicle equipped with Intelligent Speed Adaptation (what used to be known as a “governor”) a spin through London. The car limits speed to whatever the limit is on the segment — typically 30 mph.

This line struck me:

Like most motorists I want to be law-abiding. Up until now I’d believed I was. But this clever car exposes such self-delusions. Normally I try to keep to 30mph in town but in reality I must have been doing nearer 40 as I never drive this slowly.

Someone recently asked me, “why do people speed?” There’s no short answer to that question (I’ve got 250-page reports tackling the question), but one possibility that must be considered, in light of the above sentences, is that: They actually don’t know how fast they are going. Any number of studies have shown how drivers, particularly when the feedback is noisy — i.e., they’re sitting high up from the road, the car cabin is ultra quiet (or the radio loud), the road is very wide — routinely underestimate their speed.

As we’ve banged on here about many times before, these minor differences in urban speed, while inconsequential and almost imperceptible for the driver, can be of dramatic importance for the pedestrian or cyclist struck by a vehicle.