Hands-free is not enough

The other day, we heard that the U.S. NTSB would be proposing a nationwide ban on mobile phone use, and people were speculating that it’d increase sales and use of hands-free calling. I thought that would be odd, since a number of studies have made it clear that it’s mostly talking on your mobile phone that’s dangerous, whether it’s hands-free or not. There’s cognitive interference when you talk to someone who isn’t in the car with you, and having the device be hands-free only helps with the mechanical aspects, not with the cognitive ones, and those appear to be more important from a safety point of view.

And, as I expected, the proposed ban includes hands-free devices. Quoting from their news release of yesterday:

No call, no text, no update behind the wheel: NTSB calls for nationwide ban on PEDs while driving

December 13, 2011

Following today’s Board meeting on the 2010 multi-vehicle highway accident in Gray Summit, Missouri, the National Transportation Safety Board (NTSB) called for the first-ever nationwide ban on driver use of personal electronic devices (PEDs) while operating a motor vehicle.

The safety recommendation specifically calls for the 50 states and the District of Columbia to ban the nonemergency use of portable electronic devices (other than those designed to support the driving task) for all drivers. The safety recommendation also urges use of the NHTSA model of high-visibility enforcement to support these bans and implementation of targeted communication campaigns to inform motorists of the new law and heightened enforcement.

According to NHTSA, more than 3,000 people lost their lives last year in distraction-related accidents, said Chairman Deborah A.P. Hersman. It is time for all of us to stand up for safety by turning off electronic devices when driving.

No call, no text, no update, is worth a human life.

Note nonemergency use and other than those designed to support the driving task. There is no exception for hands-free devices in their recommendation.

The NTSB has no standing to force this; in the United States, the states make their own traffic rules. But Congress can back the recommendation with funding incentives, as they did with the now-defunct 55 MPH speed limit, and as they have done for laws requiring seat-belt use.

And who's driving?

I’ve often written about technology that will help us do everyday things, and I almost always advocate technology that helps, while leaving the choices with us, the control in our hands. Mostly, I think that’s what works best.

But what about when the technology is meant to improve safety in cases where we, ourselves, fail? The very point, there, is that our own choices are faulty, and the technology must fill in for us. Where’s the line between “manual override” and preventing us from casually defeating important safety protections?

We got one version of that with anti-lock braking systems. The system “knows” that people are not good at emergency braking, and that when we jam hard on the brake pedal we’re likely to throw the vehicle into a dangerous skid. Further, the ABS has information that we don’t, about exactly how the wheels are rotating and how the car is moving — at a millisecond-by-millisecond level that we can’t hope to match. And, so, apart from the fact that we control whether the brakes are on or not, the ABS controls how the brakes are applied. There is no manual override.

But what happens if the system malfunctions? What happens when it takes over the task of applying the brakes, and it doesn’t do it correctly? We’ve recently seen issues with both the electronic throttle and braking systems in Toyotas, and there have been problems with fuel injectors, cruise controls and other computerized car systems. High-end cars have detection mechanisms that augment the cruise control to keep you from getting too close to the car in front, and that warn you if there’s something behind you when you’re backing up, lest you run over something unseen. What happens when we rely on those systems and they fail?

Does that keep us from relying on such systems? Should it? If something makes us safer 99.99% of the time, does that net out better, despite what happens in the one time in ten thousand when it doesn’t work? That depends, of course, upon what it’s saving us from, and how catastrophic the failure is.

For some time, researchers have been experimenting with cars with more and more computer control — even cars that drive themselves, for long periods. That research is becoming quite mature now, and looks ready to deploy in the real world soon.

What fully autonomous vehicles will be like is hinted at by an experimental car called Boss. Built by a team of engineering students at Carnegie Mellon University in Pittsburgh, Pennsylvania, and backed by General Motors, this robotic car scooped a $2 million prize by outperforming 10 other autonomous vehicles in a simulated urban environment created for the DARPA Urban Challenge in 2007. To win, Boss had to execute complex manoeuvres such as merging into flowing traffic, overtaking, parking and negotiating intersections, while interacting with other autonomous vehicles and 30 human-driven ones.

Boss’s computer builds a model of the immediate environment by processing data from radar, laser sensors, cameras and GPS. It then uses this model, along with information such as local traffic rules, to plan the best route and provide the situational awareness the vehicle needs for manoeuvres such as changing lanes safely, or to determine whether it has priority at an intersection.

[...]

At Stanford University in California, the Volkswagen Automotive Innovation Lab has shown what might be possible. VAIL engineers have fitted a VW Passat with cameras, cruise control radar and laser sensors, allowing it to navigate a parking lot, spot an empty space and park perfectly, with or without a driver.

The claims for such technology include not only greater safety — fewer accidents, fewer deaths — but also better throughput, better fuel efficiency, lower stress (at best, human “drivers” will be able to read, work, or even sleep, as the car takes over the controls), and other such benefits. Cars will network cooperatively to share information, creating their own infrastructure.

Will we trust all that? Should we?

Could a malfunctioning — or maliciously programmed — car send false information that causes tie-ups or collisions? Could, perhaps, a malicious base station mimic dozens of cars to create a massive problem? Could radio interference isolate a vehicle that’s relying on contact with others for its information?

On the other side, though, such cars could help us navigate safely during storms and fog that confound human drivers. They could get a sleepy driver home safely. They would avoid the normal, everyday mistakes that we make on the road that cause some 50,000 deaths and two and a half million injuries each year, in addition to the property damage.

How do we balance the risks and concerns against the huge benefit we could get from “smarter” cars?

Homeland security

Via Bruce Schneier, we get an essay by Deirdre Walker, a former Assistant Chief of Police (Montgomery County, MD), about TSA searches and security. Please go read the essay; it’s worth the time.

Ms Walker says a number of important things, but there’s one particular kernel that I want to pick out, that I think is especially important to think about. It’s in these two sentences, which put the whole thing into perspective:

We have asked TSA to find the tools terrorists use and prevent both from boarding a passenger plane. We have unintentionally created an agency that now seeks efficiency and compliance more than any weapon or explosive.

That the first resulted in the second is due to a severe misapplication of basic principles. It comes from a desire to have people see that something was being done, rather than acceptance that the right way to do it is to work barely visibly. This is what happens when we turn what should be serious investigation done backstage... into a showy spectacle. This is what happens when we exchange true protective measures for publicity stunts.

Ms Walker mentions taking off shoes during the airport security check. Now, on the surface, I don’t really mind taking off my shoes. It takes little time. But I mind it because it’s entirely ineffective. It’s useless, and it’s being promoted as a useful tool in the anti-terrorist toolbox. Not one terrorist has been caught, not one terrorist act prevented, not one terrorist weapon found by having us take our shoes off.

The proponents of shoe-doffing, of course, and of our search techniques in general, will argue that we can’t know how many incidents we’ve deterred. How many shoe-bombs might have been used against us had we not scared those wielding them off with our security measures?

And that is certainly a problem with this sort of thing: how do you measure its effectiveness? The absence of a rare event — in this case, a once-ever event, a singleton — isn’t evidence that it’s been prevented. And even if it were, we can’t assume causation. But how can we possibly do any real experiments with security checks? We could certainly make people take off their shoes at some airports, and not at others. We can allow people to carry large shampoo bottles onto some flights, and not onto others. We could accept pocket knives or cigarette lighters on some flights, and not on others. And none of that would tell us anything.

Because apart from the questionable ethics involved, the fact is that all of the threats those mechanisms are defending against are theoretical; none of them has ever happened. No one has ever attacked a flight using the contents of a shampoo bottle, nor with a small pocket knife, nor with a cigarette lighter. And no one has successfully detonated his shoe.

And as the search-supporters say that proof that this is all effective comes from the lack of hijackings, we’re told that proof that the whole system works to make us safer is that nothing like 9/11 has happened since 9/11.

Only, nothing like 9/11 had happened before 9/11 either. And even if we stipulate that our security measures have made it harder to attack airplanes or to use them for attacks, it’s clear that there are many other mechanisms for attack. Taking down two large buildings in a showy manner, and crashing a third plane into the Pentagon, made a major statement. But the real terrorism would come from whittling away at our everyday freedom. It’s not so much a question of fear on entering a large building — which we might have a hope of protecting — but fear that you can’t go into a pizza joint, a deli, or a coffee shop without risking getting blown up. Fear that you can’t ride a bus without taking your life into your hands. It’s not the killing of 3000 people at once that’s truly terrifying, but the killing of 30 people at a time, or even 3, and doing it every day and everywhere.

And that’s not happening here.

It’s a good thing, too, because that, we’re doing little to stop. Because we haven’t created a system for finding terrorists and keeping ourselves safe. We have instead created a system that seeks efficiency and compliance more than any weapon or explosive.

Left turns: a follow-up

In “Green lights and left turns”, I talked about the throughput benefits of having left-turn arrows come at the end of the green-light cycle, rather than at the beginning. The following week, Joseph, at Corpus Callosum, posted an entry that advocated taking a hard line on traffic violations, in the interest of safety. Think for a minute, Joseph said, “about what it means, that we are willing to trade the lives of about ~37,000 people, per year, for greater convenience in getting to McDonald’s.”

In a comment to that entry, D. C. Sessions also mentions the left-turn arrow point:

Cheap example: left turn after (rather than before) green is proven to save lives and improve traffic flow. All it costs is a programming change, but it’s only in use in a few cities.

Noting that I talked about traffic flow, but not safety, I asked D. C. for pointers to safety information. He suggested I look into the city of Scottsdale, Arizona, and so I did. I found this on Scottsdale’s Traffic Signal Questions page:

Why does Scottsdale have lagging left turn arrows?, while other Valley cities have leading left turn arrows?

The City of Tucson has had lagging left turn arrows since 1984. Scottsdale tested lagging arrows in 1988, and discovered that this signal operation resulted in less delay and fewer accidents in our community. They were implemented citywide in 1989.

That statement is backed up by this study from 2003, and a follow-up in 2007. In the first, “A study of accidents with lead versus lag left-turn phasing”, co-authored by Scottsdale’s former traffic engineering director, they compare statistics from the cities of Mesa, which uses leading arrows, and Scottsdale, which uses trailing (lagging) arrows. Citing another report, they give some overall national statistics:

• 45 percent of all intersection accidents in the United States involve left-turning vehicles.
• 83 percent of intersections with left-turn phasing used lead phasing.
• 11 percent used lag phasing.

They further note that “Traffic engineers have differing and, sometimes, strong opinions on the merits of each phasing. Each type has valid advantages and disadvantages.” And they say that their study is only considering safety with respect to left-turn head-on (LTHO) collisions. They picked Mesa and Scottsdale because the cities are similar with respect to traffic, and both had good traffic and accident recording.

Unfortunately, the data tables aren’t included in the papers that are posted to the web (they appear to have been created with optical character recognition). But the text tells us that there was no significant difference in the safety of the two types of phasing, considering only the left-turn head-on collisions.

So we turn to the 2007 follow-up by the former Scottsdale engineer.

The 2007 study has the advantage of eight years of collision data, and the ability to do more analysis on the data they had — see the first page of the paper for the details of that.

The results of this study show:

• In general, the LTHO collision rates for the lagging left-turn arrow operation were statistically significantly less than the LTHO collision rates for the leading left-turn arrow operation.
• The percentage of all intersection collisions involving left-turn vehicles and opposing through vehicles was smaller in the city with lagging left-turn arrow operation than in the city with leading left-turn arrow operation.
• The intersection collision rates did not statistically significantly differ for intersection collisions that did not involve a left-turn vehicle.

The author speculates that a reason for the lower accident rate is that drivers making left turns at lagging-arrow intersections are more willing to wait through the green light, knowing that they have an arrow coming. They’re less likely, he suggests, to risk using an insufficient gap in traffic to try to make the turn. Of course, this assumes familiarity with the mechanism — learning, on behalf of the drivers — and so requires some time for the data to settle down and show a benefit.

Further — and I find this particularly interesting — cars that continue turning after their arrow goes away are intruding on opposing traffic very differently in the two situations. At leading-arrow intersections, they’re abruptly turning across directly oncoming traffic, while at lagging-arrow intersections, they’re turning across traffic on the cross-street. The drivers on the cross street can more easily see that there’s a car crossing the path, and can more reliably avoid a collision with it.

I’d actually be interested in seeing a panel discussion where traffic engineers debate the pluses and minuses of the two systems. But it seems to me that the lagging arrow is sometimes better (and never worse) for traffic flow, and appears to have safety benefits. So as I said in my earlier post, it looks like we should switch.

Driven to distraction: aware of the risks?

A month ago, I talked about a New York Times article about distracted driving. And last year I discussed the issue of sending text messages when you’re supposed to be paying attention to what’s around you.

This weekend, the New York Times presented another example: a 19-year-old in Utah who was texting while driving, crashed into another car, and killed two. The incident resulted in a new Utah state law that makes driving and sending text messages at the same time... illegal.

That’s fine — it certainly should be — but why does texting need to be called out explicitly? Here’s why:

Still, county prosecutors thought they were unable to charge Mr. Shaw with something other than “left of center.” For instance, if they wanted to prove Mr. Shaw guilty of negligent homicide, a misdemeanor, they would need to show he knew of the dangers or should have known of the dangers of texting while driving.

That would seem to be easy to show, don’t you think? Everyone knows texting while driving is dangerous, and you shouldn’t do it. Everyone knows. Don’t they?

Prosecutors and judges in other states already have the latitude to use more general reckless-driving laws to penalize multitasking drivers who cause injury and death. In California, for instance, where texting while driving is banned but the only deterrent is a $20 fine, a driver in April received a six-year prison sentence for gross vehicular manslaughter when, speeding and texting, she slammed into a line of cars waiting at a construction zone, killing another driver.

But if those prosecutors want to charge a texting driver with recklessness, they must prove the driver knew of the risks before sending texts from behind the wheel.

Come on! This is common sense, people; no one should have to prove anything. We just need to accept that anything that takes your attention away from driving is dangerous, and that everyone is presumed to know that. Teach this to people in diving class, put it on the driver’s license exam, and make it a condition of being allowed to drive that you know that. No one should have to prove whether you understood that it’s a hazard to, while you’re driving, read the newspaper, play a guitar, have your (fairly large) dog in your lap, shave, or do your eyelashes — all of which I’ve seen on the road at 50 miles per hour and above.

And no one should have to question whether you were away that typing on a minuscule keyboard while driving could get you and others killed.

More broadly, Mr. Swink said, drivers in Utah are now on notice that texting while driving is inherently reckless. And as drivers across the nation become more aware of that notion, he said, judges and prosecutors will feel more comfortable asking for big penalties. He said the Shaw case helped to pave the way.

Good on you, Utah. But this just needs to be standard procedure: everyone needs to be on notice, in and out of Utah.

Driven to distraction

In Driven to Distraction: Drivers and Legislators Dismiss Cellphone Risks, the New York Times tells us of Christopher Hill, of Oklahoma City. Last September, at the age of 20, Mr Hill hit an SUV at 45 miles per hour and killed its driver... because, as he freely admitted, he was using his cell phone and didn’t see the red traffic light.

Later, a policeman asked Mr. Hill what color the light had been. “I never saw it,” he answered.

Despite that “[e]xtensive research shows the dangers of distracted driving,” despite that “[s]tudies say that drivers using phones are four times as likely to cause a crash as other drivers,” people continue to use their phones, hand-held or hands-free. They make voice calls, they text. They use other devices — CD players, MP3 players, GPS systems, and others — that seriously distract them from driving. Those distractions often result in horrific collisions that would never have happened if the drivers involved had been, well, driving, rather than playing with their electronics.

We’ve always had distractions in the car. Parents have dealt with their children, people have fiddled with the radio, smokers have lit cigarettes while driving for decades. But it’s just getting progressively worse as we adapt more technology to the car. More, and smaller technology.

Remember when the car radio had a large button to turn it on and change the volume, and six large buttons to select predetermined radio stations? Compare that to finding a CD (do you find the writing as small and hard to read as I do?), taking it out of its case, ejecting the CD that’s already in the player, putting it somewhere, and inserting the new one into a narrow slot. You may well have crashed before you found the “eject” button. And scrolling through songs on a minuscule iPod screen, or entering an address with the touch-screen of your navigation system may be even more challenging to attention that should be given to the road and the traffic around you.

Then here’s another thing: the studies don’t just show that handling the cell phone is dangerous. Sure, when you have to look at the phone to enter a phone number or find someone in your address book, you’re especially vulnerable. But even with a hands-free system and voice calling, just having a conversation on the phone is dangerous — almost the same danger, whether you’re holding the phone or not.

Having a conversation with someone who is not present, it turns out, is what’s far, far more distracting than you imagine. Partly, it’s that a passenger who’s present can help keep a watch, and will at the very least adjust the conversation to allow for traffic issues. And partly, it’s that talking with someone who isn’t there is cognitively different, engaging brain functions that need to be focused on the task of guiding your one-ton hunk of metal safely through the obstacle course around you.

And yet, the denial continues:

“It’s not as if you are going to be able to take this away from people,” [Joe Berry, Ford’s director of business and product development] said of phones and other devices in cars. “They simply won’t give it up.”

Mr. Berry compared the situation to eating unhealthy foods. “We, as people, don’t want to stop doing things that aren’t in our best interest,” he said.

Well, yes, but, you see, if you stuff yourself with doughnuts, and fried cheese dipped in mayonnaise, you aren’t going to suddenly become a missile capable of taking out a hapless family two lanes over.[1] If you want to eat yourself into your grave, that may be sad, but it doesn’t affect random victims on the road. This is very different.

You are going to take this away from people, if you can get legislators with the backbone to do what has to be done and executives to enforce the laws. They key is to stop listening to the whining about what people want to do, and to start holding them accountable for what’s not safe. People want to speed, too, and people do. But that doesn’t stop us from passing laws against it and giving out speeding tickets, does it?
 

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[1] Unless, of course, you should have a major MI while you were driving, but the timing isn’t likely to play out that way.

The Chinese taints have gone too far

We’ve seen unsafe products galore, from China, and tainted foods, and, most recently, tainted milk. It’s just gone over the edge, though. They’ve despoilt one of the staples of the modern diet, food without which one might as well pack it in.

There’s now tainted chocolate.

BEIJING (AFP) — British sweet maker Cadbury said Monday it ordered a recall of China-made chocolates over safety fears in the latest fallout from the ever-widening scandal over tainted Chinese dairy products.

The company issued the recalls in Hong Kong, Taiwan and Australia after internal tests "cast doubt" on the safety of chocolates made in the company’s Beijing plant, it said in a statement.

If chocolate isn’t safe, what will become of the world?

[No, really: this stuff is no laughing matter. China needs to be totally cut off in exporting to the rest of the world until it can fix its problems in ways that can be demonstrated and monitored.]

Texting and going don't mix

I’m catching up on some news reading that I hadn’t gotten to for several days, and I find a couple of related items that just made me smack myself in the head in a gesture reminiscent of the old “I could have had a V8!” adverts:

1. California Bans Texting by Operators of Trains
2. As Text Messages Fly, Danger Lurks

The first item tells us that in the aftermath of a horrible train wreck that killed 25 people and that appears to have been caused (they’re not certain yet) by the engineer’s sending text messages when he should have been driving the train, the state of California has “temporarily banned the use of all cellular devices by anyone at the controls of a moving train.”

To which I say, “Temporarily?” WTF?

More and more states are forbidding drivers to use their hands to futz with their mobile phones while they’re driving cars, and there’s even a question about banning this stuff when one is driving a train?

Let’s look at this carefully:

1. The engineers of trains aren’t just sitting at the controls of vehicles for their own use: they are being paid for it. They’re being paid to do a job. They need to do that job. Using mobile phones, for any purpose, is not part of that job.
2. The engineers of trains arent just carting themselves around. They’re responsible for the lives and safety of hundreds of people and millions of dollars of property that doesn’t belong to them. They have a responsibility to pay attention!

The second item gives us the most profound and unexpected bit of rocket science we’ve seen in... in... well, probably ever: that doing something that takes your attention away from what you’re supposed to be doing is... distracting:

Texting while driving, or simply while crossing the street, is increasingly recognized as hazardous. “Texting automatically removes 10 I.Q. points,” one expert said.

“10 I.Q. points”? What’s that about? No, no, it’s far worse than that. It’s not that it makes you less intelligent; it’s that it takes your attention away from what you’re supposed to be doing. A dog can cross the street and avoid the cars, because it’s paying attention. A human with two PhDs and an I.Q. of 150 can walk out in front of a Chevy Suburban because she’s paying more attention to her text messages than to the traffic.

The fact is, though, that people are walking out in front of cars, that they’re driving their cars while trying to do the two-thumb dance, that they’re piloting commuter trains and not watching the signals.

Though there are no official casualty statistics, there is much anecdotal evidence that the number of fatal accidents stemming from texting while driving, crossing the street or engaging in other activities is on the rise.

I’m reminded of an old The Far Side cartoon, where a cat is pouncing on a cluster of birds. The birds are all flying away to safety, except for the one who’s listening to his Walkman.

Pay attention!

Risk: reality and imagination

Some friends and I were talking, the other day, about being stuck behind school buses in the mornings, about how the buses stop at each street or at each house, about how parents wait with the children. And about how that’s different from “before”, and whether the change makes sense.

When I was in grade school, I walked or took the public bus(!) through third grade (I was riding the public bus by myself from the age of six, paying the fare and knowing which stop was mine), and rode a school bus from fourth grade on. I walked half a mile to the grounds of another school, where some twenty kids met, hung around, engaged in horseplay, and waited for the bus to our school. There were never adults around, and we never thought there should be.

More importantly, our parents never thought there should be.

Today, we worry. We don’t want the kids walking to a bus stop in the mornings, lest they be hit by cars. We don’t want them left alone, lest they be snatched. We worry about attacks, kidnappings, sexual assaults, murders, and we lock things down to protect ourselves, our children, our families.

Does it really make sense? These things do happen, to be sure, but they happen so infrequently that the chance of something happening to you is vanishingly small. Yet you want to be sure, and, indeed, my quoting statistics that show how unlikely it is means little when it’s your child who’s been abducted, or worse. So you do everything we can to make sure.

That may be a sensible approach for a group as small as a family, but it doesn’t scale up. It simply doesn’t work to take the same precautions in our society as a whole as we do in a small group. The level of control needed is too great. The effect on personal liberties is too severe. The effort and manpower required is too large.

And so with terrorism. We are, by the nature of it, terrified of terrorism, something we remind ourselves each year on 11 September. But it doesn’t make sense. Consider this, from the Australian Sydney Morning Herald:

And yet the study reveals that almost 40 per cent of voters believe the Government should be doing more to prevent terrorism, whereas only 10 per cent believe it’s done too much.

There’s just one small problem with all this. Australians, like people in most countries, have a hugely exaggerated impression of the likelihood of terrorist attacks. Actually, make that two small problems. The other is we have an exaggerated impression of governments’ ability to prevent attacks.

[...]

None of those events gives us a realistic idea of the probability of an attack. Transnational terrorism across the world leads to an average of 420 deaths a year. With a global population of 6.6 billion, that’s not a big risk.

The chance of being killed in a road accident is very much higher. Australia’s annual road toll is four times that figure for the whole globe. And in the US, 10 times as many people are killed on the roads each year as the number killed in the unprecedented and unrepeated events of September 11.

Even the chance of contracting HIV/AIDS would be much higher. But modern politicians are much more in the business of pandering to the public’s misperceptions — and exploiting them for their own ends — than they are of setting us straight on the facts of life.

In a study of terrorism prepared for the Copenhagen Consensus project by Professor Todd Sandler, of the University of Texas, and two other economists, they conclude that “guarding against terrorism can use large resources for little reduction in risk”.

What’s more, defensive measures against terrorism “may simply change the focus of attacks (for example from hijacking to kidnaps) and even increase attacks by creating new grievances”.

Mull that over and let it sink in. And note that Americans are not significantly different from Australians in this regard. Now look at some of the main points repeated:

1. People want the government to do more to prevent terrorism...
2. ...yet the government’s efforts against terrorism are largely ineffective.
3. ...yet the government’s efforts against terrorism are very costly.
4. ...yet the risk is very low to start with, much lower than things we do every day and consider safe.
5. Politicians take advantage of our fear; it’s in their best interests to keep us afraid.

The key to thinking about this rationally is to understand that our perception of risk increases with the surprise and drama of the situation, and decreases with familiarity. We’re used to car crashes (high familiarity, low surprise), and a single crash only kills one or two people (low drama), so we downplay the risk in our minds. We’re not used to bombings; they’re unexpected, and they sometimes kill a large number of people. Moreover, the media add to the drama by showing us the sort of graphic pictures that are usually absent from coverage of the typical auto fatality. All that makes us mentally multiply the risk, well beyond reality.

What’s needed is a cost/benefit analysis to put things into perspective and show what’s worth doing... and what’s not. We’re talking about protecting lives, here, so the cost question is fraught. Still, it’s clear that we’re not willing to spend unlimited resources to save a single life, so there’s some analysis that we can do.

Think about securing your house. Here are a set of things you could do, in approximate order of cost (I’m sure you can think of others; feel free):

1. Be careful about locking the existing locks.
2. Install better locks.
3. Get a dog.
4. Install an alarm system.
5. Hire night-time security guards.
6. Hire full-time security guards.

Of course, we’ll each do our own cost/benefit analysis, and we’ll use the results to decide what to do. I could say that protecting my house protects my life, so no cost is too much. But none of us would actually decide it that way — none of us are likely to hire guards. We’d assess the risk, and pick a choice that’s the right balance between how much we think we can reduce the risk compared with how much money we’ll spend doing it.

The same goes for “homeland security”; we can throw the entire national budget at it, but not everything we do gets us much reduction in risk, and we have to consider the value of what reduction we do get, as well as the value of public perception, against the cost of the effect on civil liberties and the benefits of what else we might spend the money (and other resources) on.

And it’s the cost/benefit analysis that’s largely missing, as we do random searches of subway riders, keep watch lists that have so many names that they’re worse than useless, make people take off their shoes at the airports, and hassle the tourist who’s trying to take photos of his visit to the United States.

Limiting the speed of cars?

Kent Sepkowitz, a medical doctor, suggests, in a New York Times op-ed piece, that speeding kills and that we can solve the problem easily — that “there’s a simple way to prevent speeding: quit building cars that can exceed the speed limit.”

There’s one thing you can be sure of in life: when someone claims to have a “simple” solution, their plan is neither simple nor a solution. Such is the case here, as well, though Dr Sepkowitz has some valid points. Here’s what he gets right:

1. “Speeding is [a factor in] 30 percent of all traffic deaths in the United States — about 13,000 people a year.”
2. “There is [a] relationship between speeding and alcohol.”
3. “Americans insist on the inalienable right to speed.”
4. We could use toll-road information to compute a lower bound on drivers’ speeds, and ticket them accordingly. Indeed, I, too, have always wondered why we don’t, and I suspect, as Dr Sepkowitz does, that item 3 is the reason, and that “the public outcry would be deafening.”

So what does he get wrong?

First, and most obviously, he conflates speeding — exceeding the speed limit on a particular road — with exceeding some global maximum speed to which we could limit cars. To be sure, both are dangerous and the latter is worse. But the statistics are based on the former, and governing the maximum speed of cars would not have the effect he’s suggesting that it would.

A great many fatal collisions in which speed is a factor happen at speeds well below any reasonable maximum — say, when someone is driving 60 MPH where the speed limit is 35. We do not have the infrastructure to prevent cars from speeding, in that sense.

Speeding is not a priority for the NHTSA because, while it’s a factor in (not “the cause of”) a great many traffic deaths, it’s often a contributing factor, not the primary one. Coupled with drinking, it’s the drinking that’s the real problem. Similarly for driver inattention, impatience, sleepiness, and other factors. When we look only at cases where speed exceeded 75 MPH, the hard limit Dr Sepkowitz proposes, the case is even stronger. Which will prevent more deaths on the whole: mechanically limiting car speeds to 75 MPH, or getting everyone to wear seat belts? It’s the latter, and that’s why the seat belts are a higher priority.

It’s also not correct to say, “Speeding, after all, substantially reduces fuel efficiency due to the sheering force of wind.” It’s not that simple; if it were, we could maximize fuel efficiency as well as safety by limiting everyone to 20 MPH — and I’m quite sure that even Dr Sepkowitz wouldn’t accept that. No, given a particular combination of engine design, body design, and road, there will be a speed that optimizes fuel efficiency. That speed might be less than or greater than the speed limit, depending upon what the limit is for that particular road. “Speeding” does not use fuel inefficiently. Driving at 85 MPH probably does.

There are also good reasons to have headroom, to be able to go faster at certain times than one might normally allow. Probably, the suggested 75 MPH limit handles those cases acceptably.

All that said, I don’t mean to imply that I think Dr Sepkowitz has a bad idea here — only that it’s not as good as he thinks it is. He’s right that there’s no good reason to have cars that can go faster than 75 MPH or so on the American roads. Just because it doesn’t solve the whole problem doesn’t mean that it isn’t worth a go.

On the other hand, many of us remember the period when speedometers were limited to a maximum reading of 85 MPH — even if the car could actually go much faster. It didn’t last. Dr Sepkowitz is quite right: “Americans insist on the inalienable right to speed.”

I’ll also note that speed limits are much higher in parts of Europe — and are famously absent on sections of Germany’s Autobahn — without higher fatality rates. The roads are built for the high speeds, and the drivers are used to different habits. Training is important. It’s interesting to be riding in the left lane of the Autobahn, passing cars in the right lane as though they were standing still... and realizing that the “slow-pokes” in the right lane are going 85 MPH (130 KPH).

If you think Americans would object to having their cars’ speed mechanically limited, go suggest it to the Germans.

Hang up and drive

We have a new study that says something I’ve been saying for some time in just about these very words:

A study may shed light on why talking on a cellphone appears to make drivers prone to accidents.

The study looked at how having a conversation with someone who is not present competes with those parts of the brain needed to perform visual tasks.

Safety statistics have shown for some time that talking on a mobile phone is bad for driving, and that using a hands-free system only helps somewhat. Some have been as extreme as saying that, from a safety standpoint, just talking on a mobile phone while you’re driving is as bad as being legally drunk:

“We found that people are as impaired when they drive and talk on a cell phone as they are when they drive intoxicated at the legal blood-alcohol limit” of 0.08 percent, which is the minimum level that defines illegal drunken driving in most U.S. states, says study co-author Frank Drews, an assistant professor of psychology. “If legislators really want to address driver distraction, then they should consider outlawing cell phone use while driving.”

Psychology Professor David Strayer, the study’s lead author, adds: “Just like you put yourself and other people at risk when you drive drunk, you put yourself and others at risk when you use a cell phone and drive. The level of impairment is very similar.”

“Clearly the safest course of action is to not use a cell phone while driving,” concludes the study by Strayer, Drews and Dennis Crouch, a research associate professor of pharmacology and toxicology. The study was set for publication June 29 in the summer 2006 issue of Human Factors: The Journal of the Human Factors and Ergonomics Society.

The study reinforced earlier research by Strayer and Drews showing that hands-free cell phones are just as distracting as handheld cell phones because the conversation itself — not just manipulation of a handheld phone — distracts drivers from road conditions.

Note that carefully: these studies say that even if it’s hands-free, using a mobile phone is dangerous while you’re driving. It engages different parts of your brain when you talk with someone who’s not present, compared with talking with someone who’s sitting there with you — parts of your brain that you need to reserve for the task of driving, of paying attentioni to your surroundings, of responding to road and traffic conditions.

We all know how distracting a conversation can sometimes be, even with someone who’s in the passenger seat. These studies provide clear evidence that it’s even worse when your conversation partner isn’t there with you.

Most of us do use mobile phones while we’re on the road. Think about this. Limit the usage to what’s absolutely necessary. Pull over, and have the conversation from the side of the road.

Hang up and drive.