Are We Ready for Mandatory Alcohol Detectors in Cars?

 

Drunk driving has been a problem ever since automobiles were invented.  The alertness needed to control a motor vehicle is incompatible with drinking more than a certain amount, and as a consequence of ignoring this fact, 13,400 people in the U. S. died in alcohol-related crashes, according to a recent AP news report.  That may be about to change, because in response to a law passed by Congress in 2021, the National Highway Traffic Safety Administration (NHTSA) announced on Dec. 12 that it is going to require all new passenger vehicles to have a device that will prevent drunk driving.

 

The NHTSA rule will not go into effect for a year or two, at least, because the agency's notice of proposed rule making first allows manufacturers to provide information about the state of the technology so as to have an orderly rollout and reasonable requirements once the rule is finalized.  But unless Congress changes its mind, sooner or later all new cars will have this feature—or bug, depending on your point of view.

 

So-called "ignition lockout" devices are not new.  A cursory search of the Internet turns up dozens of papers and project descriptions to implement versions of this technology.  It appears that some jurisdictions already require certain people convicted of drunk driving to install a lockout device on their car before they are permitted to drive again.  Some of these gizmos are pretty inconvenient—imagine having to blow into a tube every time you start your car.  But it's better than not being able to drive at all.

 

The AP article says that the new required device won't have a tube for drivers to blow into, and the average driver may not even be aware of its presence.  The optimum technology hasn't been decided on yet, but leading candidates include a sensor that would check the driver's breath from a distance (maybe mounted in the steering wheel?), or an optical spectrometer that would derive blood alcohol content from reflectance measurements on a finger. 

 

From a technical point of view, one can ask what the acceptable rate of false positives and false negatives are going to be.  For sober drivers and those who haven't consumed their legal limit, false positives will mean that your car won't start until the device decides that you're really sober.  Users of alcohol-based mouthwashes and breath-freshener sprays will have to avoid using them just before getting in the car in the morning.  This in itself is not a major problem, but other factors could cause false positives as well.  For the finger-spectrometer device, what if you happen to wear gloves?  Too bad, you'll have to take them off to drive. 

 

And then there's the question of setting a threshold.  As the instrument itself can be backed up by sophisticated statistical software, it may take other factors into account:  the weight of the driver (easily obtained from a strain gauge in the seat), the driver's motions as monitored by pedal and steering wheel activity, and history of alcohol use as detected by the system in the past.  But no system is going to be perfect.  We can expect some unanticipated problems when the systems are first deployed widely among drivers who don't drink, because there's nothing like the real world to come up with situations that even the most imaginative engineer can't predict.

 

Even worse will be the false negatives:  cases in which the driver is really drunk but the system doesn't detect it.  Habitual drunk drivers will have a strong motivation to defeat the system, and designers will have to take measures to ensure this doesn't happen.  "See that little hole in the steering wheel?  Plug it up with chewing gum and you can drive no matter how many you've had." Tricks like that will have to be prevented somehow.

 

Reducing the thousands of deaths annually due to drunk driving is worth something, certainly.  And adding one more required system to automobiles is not going to be noticed along with the many hardware and software enhancements—assisted driving chief among them—which are already being implemented voluntarily by carmakers. 

 

But an alcohol-detection system is different in kind from other systems, in that it monitors the driver's condition independent of how well he or she drives.  You can make the case that automatic braking systems step in and remove control from the driver when the system decides it's necessary, but that is determined by immediate road circumstances to avoid an imminent crash.  An alcohol-detection system uses a chemical sensor to conclude that the "meat system" called the driver is unsuitable for use, and simply shuts down the car until the driver sobers up. 

 

This may be the first step toward driver evaluation that is already implemented in some ways elsewhere.  "Dead man" lockout systems in certain types of industrial equipment require that a person always be touching the controls or holding a pedal down, and if the operator ceases to do so, the equipment automatically stops.  One can imagine alertness tests using subtle cues such as eye motion in response to instrument-panel changes, and if the car decides you're too sleepy to drive, it tells you to pull over or else.  Or else—what?  Stopping in the middle of traffic wouldn't be a good idea, but unless the car is semi-autonomous already, it's hard to think of what to do with a sleepy driver other than to tell him or her to get off the road, and hope that the driver obeys. 

 

Like it or not, all new cars will eventually have the alcohol-detection feature, which is already being required next year in some European Union countries.  And we will have to deal with the consequences, whatever they may be.  Reducing the number of drunk-driving crashes is a highly worthwhile goal, and if it means a few non-drinkers will be inconvenienced by false positives now and then, it's probably worth it. 

 

Sources:  The AP article "US agency takes first step toward requiring new vehicles to prevent drunk or impaired driving" was published at https://apnews.com/article/alcohol-breath-test-devices-required-new-vehicles-2a2e2862691ecea396df3ab66d4440c6.  I also referred to a website of the Chinese firm Winsen (which makes alcohol-vapor detectors) at https://www.winsen-sensor.com/knowledge/alcohol-detection-engine-lockin-to-prevent-drunk-driving.html. 

Will More Auto Safety Investigators Save More Lives?

Last Friday, the U. S. National Highway Traffic Safety Administration (NHTSA) announced that it was planning to improve the way it keeps tabs on automakers and the safety of their products.  NHTSA administrator Mark Rosekind admitted that the changes were largely inspired by his agency's failure to catch the GM ignition switch problem early enough.  The defective switches on older-model small cars such as the Saturn Ion and the Chevy Cobalt could accidentally cut power to both the engine and the vehicle's airbags, and have been identified as the cause of over 100 deaths and 200 injuries that took place before a massive recall of some 2 million vehicles last year to fix the problem. 

Rosekind acknowledged that although his staff had access to some of the data on the switch problem, they didn't understand that the switch could disable the airbags, and so in two reports issued by the agency, there are calls for improved technological expertise and more investigators in the agency's Office of Defects Investigation (ODI), which currently has about 60 full-time employees.  The report calls for increasing that number to 150, and maybe more.  Rosekind says that NHTSA has already undergone a "culture change" which relies less on the automakers to do self-policing and more on the agency to hold automakers accountable for producing needed data, and also for the agency to do more on-the-ground accident investigation itself.

The question here, as in any change of resources to address a problem with engineering implications, is:  will it do any good?  And will the good that might result be worth the resources expended?

As bureaucracies go, the NHTSA's ODI is pretty small compared to the total number of non-military Federal goverment employees—about 2.7 million people in 2014.  A few million dollars will give the NHTSA all they're asking for and more.  If you asked any of the relatives and friends of those 100 people who died because of defective GM ignition switches about this proposal, they would say the expenditure is worth it if it will save even one life in the future.  And here we get to an issue that tends to come up a lot in discussions of engineering ethics:  the monetary worth of a human life.

I'm not going to waste time playing with dollar/life quotients, because doing that means you have slipped into the never-never land of utilitarianism.  The philosophical approach to happiness called utilitarianism is conveniently (if not entirely accurately) summarized by the phrase "the greatest good for the greatest number."  It has a sneaky kind of appeal to engineering types, because it holds out the (false) promise of reducing complex morally-freighted issues to a straightforward process of mathematical optimization. 

I reject utilitarianism for a number of reasons.  While it has limited usefulness in extreme cases—it tells you, for example, that placing the value of a human life at zero is unwise—the thing usually falls apart well before you can actually sit down with a calculator and do a mathematical operation that will tell you which of several alternatives in an ethical problem is the right one.  It falls apart for me because the very act of putting a dollar value on a human life makes one no different in principle from the slave traders who did exactly that for profit.  It is simply a thing not to be done.

Well, if we can't make the situation into an optimization problem in mathematics, how should we decide if giving the NHTSA more bucks to hire more inspectors is a good idea?  To begin with, a little background might be helpful.

The history of U. S. auto safety has been one of gradual but cumulatively remarkable improvement, starting with the adoption of safety glass in the 1920s by Ford Motor Company, and progressing to seat belts, air bags, and many other safety-related technologies, only some of which were federally mandated.  The result of these improvements has been a pretty steady decline in deaths due to automobile accidents from a high of nearly 3 per 10,000 people per year in the 1930s to about 1 per 10,000 today.  So to begin with, things are getting steadily better, and if self-driving cars realize their early promise, the operator errors and drunk-driving accidents that cause most crashes today may largely go away too.  In the perspective of these numbers, while the 100 or so people who died in the GM switch accidents died needlessly, they were only 0.3% of the 30,000 or so people who died in auto accidents in each of the last few years. 

Ironically, it looks like the public is less upset when a single bad guy can be identified as the cause of a fatal crash, than when the immediate cause is something mechanical like a weak ignition switch spring.  This has nothing to do with mathematical optimizing of resources, and everything to do with how people perceive risk and danger.  You get in your car and tool out on the highway.  Maybe there's a drunk driver out there, but you think you can do something about that.  You can see him weaving around and steer out of his way, for instance.  But some un-thought-of hidden mechanical defect like a defective ignition switch—there's nothing you can do about that.  It's a lot scarier, and the news media know that, and the automakers know that.  Which is why they have been highly motivated to avoid causes of safety recalls, and deeply regret the ones that slip through their own bureaucracies (as the GM ignition switch problem did) and cause only a few verifiable fatalities.

So what is the bottom line here?  I think the bottom line is, there is no bottom line.  This is not an accounting problem.  Maybe three times as many investigators at the NHTSA will make the automakers three times as vigilant to catch the next major safety flaw before it gets built into millions of cars.  While that would be nice, I doubt it will happen, and I don't know of any objective way to tell whether it's happened after it happens, if in fact it does happen.  But the public has read in headlines that the feds are doing something about the problem, and that perception itself, rather than any meaningful actions that may happen afterwards, may have been the main point in this exercise.

Sources:  The Associated Press article on the NHTSA reports was carried by a number of outlets, including the Los Angeles Times under the headline "U. S. auto safety agency admits flaws, starts reform after GM case" at http://www.latimes.com/business/la-fi-hy-nhtsa-gm-20150605-story.html.  I referred to the Wall Street Journal for the statistic on the current (2014) number of Federal employees at http://blogs.wsj.com/economics/2014/11/07/the-federal-government-now-employs-the-fewest-people-since-1966/.  I also referred to the press release of June 5 at the NHTSA website, http://www.nhtsa.gov/About+NHTSA/Press+Releases/2015/nhtsa-forming-new-safety-teams, and the Wikipedia articles "List of motor vehicle deaths in U. S. by year" and "Windshield."  I most recently blogged on the GM ignition switch issue on April 7, 2014 at http://engineeringethicsblog.blogspot.com/2014/04/the-gm-ignition-switch-recall-too.html.