Conspicuity for Self-Driving Cars: An Overlooked but Crucial Capability


By Dr. Lance B. Eliot, AI Trends Insider

Have you gone to the mountains for a hiking trip and ever been offered advice about how to handle an encounter with a bear?

There are two schools of thought about dealing with bears.  One approach involves being as loud and obnoxious as you can be, if you encounter a bear.  This includes yelling forcefully at the bear, raising your arms above your head, waving your arms back-and-forth, and trying to be as aggressive looking and sounding as you can be. Some even say that you should pick-up a small child (if they happen to be handy and are your child), and hold the child up to make you look larger and fiercer. Or, you might instead open your coat and spread it out to look larger, along with standing as tall as you can and possibly even standing on a tree stump to look taller.

That’s the “being conspicuous” school-of-thought about dealing with bears. Meanwhile, there are some that say you should take the opposite tack. You should avoid being aggressive. Stand still. Keep your arms pinned to your side. Don’t spread your legs and instead keep them tightly close together. Make no direct eye contact with the bear. No screaming, no yelling, no noises at all. This is the “being inconspicuous” approach to bear interaction.

Which approach should you use?  The answer is that it all depends.  If you have come upon a bear and it is threatened by you, for example if its cubs are nearby, in that context you might be better off with the conspicuous way of interacting with the bear.  On the other hand, suppose that you are crossing a stream and there is a bear that is near the water and it happens to see you.  Assuming that there is nothing threatening going on, you probably would be wiser to use the inconspicuous method.  You would act almost like you hadn’t seen the bear and just quietly continue on your journey.

What does this have to do with self-driving cars?  The answer is simple and actually very telling. We need to be enabling self-driving cars with the right kinds of AI-directed conspicuity.

At our Cybernetics Self-Driving Car Lab, we are one of the few self-driving car software makers that is delving into conspicuity.  It is something that almost none of the other self-driving car makers are doing anything about.  I’d say they are missing the boat.

What is conspicuity for self-driving cars?  It is the proper and appropriate utilization of the various ways that a self-driving car can appear either conspicuous or inconspicuous. Notice that we are including being conspicuous or inconspicuous. Many get derailed on this topic by only considering the act of being conspicuous and fail to also consider the other side of the coin, namely being inconspicuous.

Let’s take an example of being conspicuous while driving a car. I was driving down Pacific Coast Highway the other morning, it was early in the morning and the sun had not yet risen. In addition to the darkness, there was a dense coat of fog too. Visibility was very poor.  Any car ahead of me was pretty much swallowed into the fog if I was more than a half dozen car lengths behind it. I am sure that cars behind me were having a hard time seeing my car too. All in all, this is a pretty dangerous situation.  Suppose the car ahead of me suddenly slams on their brakes, I’d have little reaction time and would likely ram into them. Suppose there was debris on the roadway, I’d likely not see it until running over it. Etc.

Some cars were being inconspicuous. By this I mean that they had no headlights on, and they were silently moving along at 55 miles per hour like a hidden shark in the sea. This was scary for them and the other cars. Fortunately, most of the cars did turn on their headlights, increasing their conspicuousness. They were more readily visible than were the cars without headlights on. The cars that wanted to be more conspicuous were driving more cautiously too, often tapping their brake lights, which was a kind of subtle but obvious signal to the car directly behind them.  Basically, the driver was saying to cars behind them that they should be driving with caution and the easiest means to do so was by repeatedly tapping their brakes to illuminate their rear brake lights.

I opted to also use the conspicuous methods. In fact, I went even further and was occasionally using my car horn, doing a light tap of the horn. This provided another sensory clue, besides the visual clues of the headlights and brake light.  By using sound, I hoped to be even more conspicuous.

One car even turned on its emergency flashers, even though it wasn’t stopped by the side of the road. It was still driving, but now driving real slowly and even slightly swerving right and left in the lane.  This driver seemed to be wanting to prevent those speed demons that were driving like it was a perfectly sunny day from zooming around them and possibly getting into an accident up ahead.  This was not necessarily for the benefit of the speed demon, but more so for the driver that didn’t want the speed demon to create an accident and then have that driver get mired into it (see my column about self-driving cars and accident scene traversal).

We should expect that our self-driving cars will be able to discern when to use conspicuity. The AI should be gauging the nature of the driving situation and opt to either be conspicuous or inconspicuous, depending upon what is most sensible for the given circumstance. As mentioned, few of the self-driving car makers are thinking about this, let alone developing the AI for it.  They are assuming that whatever conspicuity is needed will be done by the human occupants that are in the self-driving car.  This though does not make a lot of sense.

If the self-driving car is a level 5 (see my piece about the Richter scale for self-driving cars), we would by definition assert that the car must be completely driven by the AI without any needed human intervention. Having a human occupant have to turn on headlights, tap brake lights, sound horns, these are all actions we expect of a driver, not of a passenger.  Furthermore, the level 5 cars that are being envisioned won’t necessarily even provide a means for a human occupant to invoke those aspects, such as not having access to the brakes or not having access to the horn. This is something that needs to be reconsidered, by the way, and a future column will be addressing.

For a level 0 to level 4 car, there is a human driver that is expected to pick-up the slack of when the self-driving car cannot figure out what to do. In those instances, the other self-driving car makers are just assuming that the human will take care of turning on or off the headlights (other than when a rather “dumb” sensor realizes it is dark outside), or turning on the emergency flashers, or using the horn.  Though this is going to be physically possible to have the human driver do this, I think it puts a burden onto the human driver that we could use the AI to aid.

Please note that I am not saying that we would prevent the human driver from doing those actions, and I would advocate they should be able to do so, but instead saying that we should rightfully expect that the self-driving car will “know” when to use those conspicuity approaches and then use then when needed. Otherwise, the AI is missing out on a vital part of the driving task.

Some pundits will argue that conspicuity is not a vital part of the driving task. They would say that driving the car has little to do with the headlights, the emergency flashers, the horn, etc.  They would say these are aspects for humans and that a self-driving car doesn’t need to care about humans.  These utopian world pundits are confused. They think that all cars on the road will be self-driving cars. Those self-driving cars will communicate via V2V (vehicle-to-vehicle) communications, and the days of using a horn on a car will fall into the past.  Wake-up!  That’s years and years away. For quite some time we will be faced with a mixture of self-driving cars and human driven cars.  Self-driving cars must be able to interact with and understand the behavior of human driven cars.

A human driver is apt to notice another car, whether it is a human driven car or a self-driving car, if that car is being conspicuous. My example of driving in the fog is a handy illustration of this. A self-driving car in the fog would normally want to be as conspicuous as it can, alerting other cars to its presence. This might involve not only having headlights on, but also purposely tapping the brakes to illuminate the brake lights. AI developers don’t get that idea at first, in that they think the only reason to tap the brakes is because you are trying to slow down the car.  That’s one aspect of brakes. Another is that we currently use rear brake lights to warn drivers behind us that we are using our brakes.  You can use that warning system for another purpose, not necessarily because you are going slower, but just to visually jolt the driver behind you with the quickly flashing brake lights.

Some purists would say that with self-driving cars we won’t need brake lights anymore.  The radar and other sensors will detect that the car ahead is slowing down, i.e. using its brakes.  Well, that’s decades away before we see cars abandoning rear brake lights. They are here, they are here to stay. Human drivers know that they can use the brake lights for more than just braking. Same with the horn. Purists say that we won’t have horns in cars anymore, no need for them in an all self-driving car era.  Again, we’re got horns and we’re going to keep with horns for the foreseeable future.

Just like we discussed that when confronting a bear that sometimes it is best to become conspicuous, so too is the same for a self-driving car.  Besides my example of being in the fog, let’s look at some additional examples.  I was driving on a curving road in the mountains.  As you came to a curve, you could not see around the bend.  The road was very narrow. To my right was the mountain, and to my left was a sheer cliff. There were other cars coming down the hill, while I was driving up it. Some of those cars were doing a lousy job of making the bends, and would swerve over into the opposing lane as they did so. This was a situation waiting for something really bad to happen.

I used my headlights by switching from low bean to high beam, which cast a bright light across the curve and helped to warn an oncoming driver that there must be someone else coming around the curve. I used my horn as I went into the curve, in hopes that the other driver might here my car coming.  Would a self-driving car do this? It certainly could, and it certainly should. But, if the AI has not been trained to do this or developed to do it, then the human driver or human occupant has to fend for themselves.

Some of the ways for the AI to make the self-driving car more conspicuous include:

  • Use of emergency flashers
  • Horn with a light touch
  • Horn full on
  • Pumping the brake lights
  • Headlights
  • Low beam and high beam of the headlights
  • Turning headlights on and off repeatedly
  • Weaving
  • Slowing/speeding up
  • Use of windshield wipers
  • Use of spray from windshield wipers
  • Etc.

Each of the above should be used sparingly and only when appropriate. Also, they can be used in combination, such as my story about driving on the curving mountainous road and using both the headlights and the horn. In the future, some are predicting that self-driving cars will be outfitted with external advertising displays and be like driving billboards. If so, that’s another aspect that could be used to be conspicuous, by displaying messages or indications on that billboard capability.

The self-driving car could even potentially engage the use of the occupants of the car to help the self-driving car appear more conspicuous.  I was driving recently during prom week, and there were cars of high schoolers that had their windows rolled down on the cars and were yelling and screaming, and their arms were protruding outside of the car and they were making quite a commotion, having a real party as they drove on their way to the prom. Presumably, a self-driving car could leverage the human occupants by asking them to do something like this, when needed, and therefore make the self-driving car even more conspicuous on the roadway.

So far, we’ve discussed having the self-driving car look conspicuous. Would it ever want to be inconspicuous?  Here’s an example.  Some say that drunk drivers often aim at other cars on the roadway that are conspicuous. If your car has become disabled and you are stopped on the side of the freeway, some believe that you should make your car conspicuous so that other drivers will avoid hitting your stopped car.  Others say that the drunk drivers, those of whom are most apt to hit your disabled car, are actually attracted to a stopped car if it is showing flashing emergency lights or otherwise readily visible. In their drunken state, they are drawn to it, like a moth to a bright light.

If you believe it is better to remain inconspicuous in that circumstance, you’d want your self-driving car to be inconspicuous. I say this because some self-driving car makers are assuming that if your car becomes disabled, you would always want it to be as visible as possible.  Not necessarily the case.  You might want your car to blend in. You might want your car to be hidden rather than being an attractor.

Self-driving cars not only need to know when and how to best use these conspicuity aspects, they also need to know how to interpret conspicuity that is being utilized by other cars.  If a self-driving car comes upon a human driven car that is honking its horn, will the self-driving car even know that’s happening? Few of the self-driving car makers are outfitting audio pick-up capabilities onto their self-driving cars. Even if such a sensor is available, the AI needs to determine what is the nature of the sound, what does the sound mean in the situation itself, and what action needs to be taken (see my piece on emergency vehicles in which I discuss sound there too).

We know that when we encounter bears that sometimes it is better to be conspicuous rather than inconspicuous, while other times it is the other way around. Self-driving cars need to know how to leverage their ability to be conspicuous and/or inconspicuous in everyday traffic situations and also in more unique one-off driving tasks. The conspicuity of the capabilities of the car, and the situational awareness are all aspects that the AI must consider. It might seem like a minor thing to most self-driving car makers, but when you have self-driving cars interacting with human driven cars and with other self-driving cars, they are doing a dance that involves showing to each other what is happening on the roadway. Having a self-driving car that is oblivious to conspicuity puts it at a disadvantage on the roads, and furthermore can cause it to either increase the odds of an accident or at least not be as aware of a potential accident that could have been avoided by being more conspicuous.  Self-driving cars need to know how to actively participate in the daily dance of traffic. Drive safely out there.

This content is original to AI Trends.