Human And Autonomous Driving: A Deadly Mix?

"Who's in charge here?"  If people in an organization can't give a clear answer to that question, chances are the organization is in trouble.  And something along those lines may apply to cars as well as to human organizations.  That's the lesson we can draw from the preliminary report released by the U. S. National Transportation Safety Board (NTSB) last Thursday, May 24, concerning the fatal collision between a pedestrian and a semi-autonomous vehicle operated by Uber in Tempe, Arizona last March 18. 

To summarize the accident, around 9:39 PM on that Sunday night, Elaine Hertzberg chose to walk her bicycle across a divided street in between crosswalks, in a section of road that was poorly illuminated by streetlights.  She was not wearing reflective clothing and her bicycle had no side reflectors.  She apparently did not see the oncoming car until just before the collision.  Subsequent toxicology tests showed traces of marijuana and methamphetamine in her system.  Regardless of her condition, it's the responsibility of drivers (or the car's computer) to look out for the behavior of all pedestrians, even those who aren't behaving with normal alertness.  And if this responsibility is split or ambiguous, trouble is brewing.

An in-cab video released after the accident shows that the car's driver was studying something below the windshield in the cab until she saw the pedestrian just before the accident.  In my earlier blog on this incident, I mistakenly speculated that she was looking at her cellphone instead of the road, but it turns out she was monitoring a display of the self-driving car's behavior, as part of what was basically a research project in which the driver would take the car out on prescribed routes to test its systems. 

The most informative piece of evidence in the NTSB preliminary report concerns the state the car was in just before the crash.  The Volvo was equipped both with the latest Volvo-engineered safety systems, including a collision-avoidance system, and also with Uber-installed computer control.  Probably to avoid interference between the two systems, the Volvo safety controls were disabled when the Uber computer was set to operate the vehicle.  The Uber computer system is able to determine when emergency (hard) braking maneuvers are needed, and is capable of executing them.  But at the time of the accident, the emergency braking function was disabled, as Uber found it had led to erratic behavior.  The operator was apparently aware of this setting and of her responsibility to take emergency actions as needed, in addition to monitoring the vehicle's operations on the screen and "tagging events of interest for subsequent review." 

People can do only so much at once.  Abundant research has shown that too many distractions degrade a driver's ability to respond to unexpected emergencies.  Uber was basically running an experiment requiring significant driver attention while operating their vehicles on public roads.  It didn't take too long for the unfortunate combination of a driver distracted by monitoring tasks to coincide with a pedestrian whose attention was clouded to lead to a tragedy, and to suspension of Uber's experimental autonomous-car program, plus numerous calls on the part of state and federal lawmakers for a slowdown in the deployment of autonomous vehicles.

The final report from NTSB on this fatal accident will probably not come out until next year.  But their preliminary report shows how things can go wrong tragically under the current regime of what are called level-2 and level-3 autonomous driving systems.  The five-level ranking system goes from Level 0, which is what I can do in our 1955 Oldsmobile (no computer within miles) to the hypothetical Level 5, the yet-to-be-realized situation in which the self-driving car performs absolutely all driving functions and the passenger's participation is limited to telling the car where to go when he or she gets in. 

No one has yet deployed a Level 5 vehicle, and getting there will require extensive testing of lower-level systems in the real world.  Testing involves risks and unknowns—otherwise you wouldn't learn anything from it.  The dicey problem faced by autonomous-vehicle developers has always been to strike the right balance between exposing their systems to a wide enough variety of real-life situations to learn enough to improve them, and not taking so many risks that one of the close calls turns into a severe injury or fatality, as the Uber accident did.

One of the fond hopes of self-driving-car promoters is that once we get to the point where their well-designed systems are extensively employed, automotive fatality rates should start to decline steeply.  Nobody (well, almost nobody except a few suicidal maniacs) wants to die in a car wreck, and so from a utilitarian perspective, if a few people die during early-phase testing of self-driving cars, but then as a result thousands get to live who would otherwise have been killed by cars driven by people, that's a good tradeoff.

But that cold mathematical view doesn't appeal to our emotional side, and so the media and legislators react to a single fatality in a way that seems out of proportion.  I'm not sure it is, though.

What we may be seeing is part of a very normal process of social self-regulating feedback that has led to improvements in safety ever since the dawn of the Industrial Revolution.  The first thing that has to happen in this process, unfortunately, is that somebody gets killed.  And the reason they were killed has to do with a new technology.  The bad publicity attracts attention from the public, who is now less inclined to welcome the new technology; those in the position to regulate the technology, such as legislators;  and the promoters of the technology itself, who are moved to improve safety out of self-preservation.  Laws or regulations are enacted by legislators or private entities such as insurance companies, and the new industry sometimes imposes new rules on itself.   The causes of the original fatalities are mitigated or removed, and life goes on with the new technology, which in the course of time becomes old and familiar.  This happened with steamboats in the 1800s, it happened with human-driven automobiles in the early 1900s, and it appears to be happening with self-driving cars now.

As long as we don't get into some kind of prohibition panic and ban all self-driving cars forever, reasonable rules about testing new systems and deploying market-ready ones can be devised.  Compromises will have to be made.  Even if all cars were Level-5 quality tomorrow, a few people would still die in car accidents.  But chances are there would be a lot fewer than 40,000 or so per year, which is what the U. S. automobile fatality rate is running at today.  And many of those fatalities are caused by distracted drivers, including the Uber driver who had too many things to watch on the dashboard, and failed to see the pedestrian until it was too late.

Sources:  A news report summarizing the NTSB findings appeared on May 24 on the Reuters website at https://www.reuters.com/article/us-uber-crash/ntsb-uber-self-driving-car-failed-to-recognize-pedestrian-brake-idUSKCN1IP26K.  The preliminary report itself can be downloaded at https://www.ntsb.gov/investigations/AccidentReports/Reports/HWY18MH010-prelim.pdf.  I first blogged on this incident on Mar. 26, 2018 at http://engineeringethicsblog.blogspot.com/2018/03/self-driving-car-kills-pedestrian.html.

Vision Zero: Realistic Goal or Illusion?

About a week ago, I was involved in a very minor collision that slightly dented my car’s rear bumper cover.  When I took the car to a body shop to get an estimate for the repair, I picked up a magazine published by the American Automobile Association and read about something called Vision Zero. 

Vision Zero is a program aimed at reducing auto-related fatalities to the point that nobody dies (involuntarily, anyway) in a car accident anymore.  It originated with legislation passed in Sweden in 1997, and has since spread to countries throughout the world.  While I am not aware of much U. S. federal legislation pertaining to it, a number of U. S. cities have bought into it, including Austin, Texas, just up the road from me.

There have been auto safety programs ever since there were automobiles, but this one is different.  For one thing, according to the Wikipedia article on it, it consciously rejects the cost-benefit thinking that lies behind so much engineering-ethics analysis.  As a practical matter, we as a society appear to have made the compromise that we want the benefits that cars bring to our lives, and we are willing to pay the price of the 40,000 or so U. S. traffic deaths that happen every year.

Vision Zero rejects this line of thought, and says no amount of driving and the good things it brings are worth one human life.  It asks what we can do to make driving so safe that you’d have to work really hard to kill yourself or another person with a car.  And it turns out, there’s a lot that hasn’t been done yet.

The Vision Zero approach concentrates on roadways and associated infrastructure, and what can be done to make sure that any accidents that happen don’t result in fatalities.  One simple example is intersections.  On streets where traffic is busy enough to warrant a two-way stop sign, you can have a fatal collision if somebody on the side road runs the stop sign and a car on the main road is going fast enough to result in a fatal accident.  One Vision Zero solution to this is to replace stop-sign-equipped intersections with rotaries (traffic circles).  Anyone who’s paying the slightest bit of attention to their driving will see a rotary coming up and slow down before going around it at a speed that might result in a collision, but one that would be little more than a fender-bender, not a fatal crash. 

The same philosophy can be applied to highways.  Vision Zero proposes building medians on any road where two-way traffic goes fast enough that a head-on collision is likely to be fatal, namely a speed of about 43 miles per hour (70 km/hr).  In the relatively small and centrally-governed country of Sweden, maybe this is a feasible goal.  But in Texas, which is half again as large, making all rural roads divided highways would cost many billions of dollars and take years to do, if not decades.  Of course, you could just pass a law limiting the rural speed limit to 45 mph, but Texans are not Swedes, and that law might not be observed any better than the one rumored to be still on the Texas books that prohibits you from carrying barbed-wire cutters in your back pocket. 

A goal that complements Vision Zero has been adopted by Volvo, the automaker that is still largely based in Sweden but now owned by a Chinese company.  In 2016, Volvo announced its intention to reduce auto fatalities in its new vehicles to zero by 2020.  That’s only two years away now, but as of 2016, there were already nine different car models (one of which was a Volvo) in which no fatalities were recorded in the U. S. in the period 2009 to 2012.  Some of these may have been low-volume super-luxury cars that owners treat more like jewels than like transportation, but the fact remains that a zero-fatality vehicle is a real possibility.

Add to the mix the prospect of autonomous vehicles and all the safety-enhancing systems that go with those, and we may have a realistic chance of seeing the day come when dying in a car wreck might be as rare an occurrence as being killed by lightning, which happens to about 50 U. S. residents a year.  I suppose there will always be the occasional suicide or attacker who chooses to use a car as a weapon.  But even these folks may find it hard to defeat the future safety features that will come with autonomous vehicles, even if you choose to drive it by yourself.  The decision of whether to make such features optional or hard-wired is one that car makers will have to ponder.  There will be die-hards who will never adapt to autonomous cars, and there will be others such as disabled people who will be more than happy to let the car do all the driving.  And all of this will have an unknown effect on sales, but by and large I suspect most people will acquiesce in the safety features as long as they don’t keep you from doing what you want to do in normal travel situations.

As for Vision Zero, the only thing that keeps it from happening tomorrow is limited resources.  As I pointed out, making the road infrastructure so that it’s very hard to die in a car wreck costs a great deal of money.  That is why adoption of Vision Zero in the U. S. is spotty, with places like Austin going in for it but other cities hanging back.  With the complicated mix of local, state, and federal funding for roadways in this country, it may be a long time before we see Vision Zero applied with anywhere close to the uniformity that places like Sweden can achieve.  But miracles can happen, and maybe we will get tired enough of reading about senseless and preventable automotive deaths to unite behind a movement that, although I have never seen this phrase applied to it, is really pro-life.

Sources:  In addition to the Wikipedia article “Vision Zero,” I referred to a CNN article from 2016 at cnn.com/2016/01/20/luxury/volvo-no-death-crash-cars-2020/index.html.  I obtained the estimate of 2017 traffic deaths from https://www.cnbc.com/2018/02/14/traffic-deaths-edge-lower-but-2017-stats-paint-worrisome-picture.html.  Austin’s Vision Zero website can be viewed at https://austintexas.gov/visionzero.  And as mentioned, I first learned about Vision Zero in a print publication of AAA Texas, although I can’t recall the citation information.