How would a robocar handle an oncoming tsunami?


Recently a reddit user posted this short video of an amazingly lucky driver in Japan who was able to turn his car around just in time to escape the torrent of the tsunami.

The question asked was, how would a robocar deal with this? It turns out there are many answers to this question. For this particular question, as you'll see by the end, the answer is probably "very well."

Let's start with the bad news. On its own, built in a world where few thought about tsunamis, there is a good chance the vehicle would not handle it well. The instinct for most developers is to be conservative and cautious when facing an unknown situation. The most cautious thing is to do nothing, to just stop and perhaps ask for help from a person in the car or a remote center. Usually if you don't understand the situation, doing something is much riskier than doing nothing. Usually -- but clearly not here.

This situation might be viewed as similar to something you might expect a car to have programming for -- something is approaching fast towards you. Cars will probably have logic to deal with a car coming the wrong way down their lane, and this looks a bit like that. It's actually stuff coming in both lanes. We can imagine the car might have logic to attempt to retreat in that situation, though this isn't going to look too much like anything the sensors have seen before. With 3D sensors, though, it will be clear that something huge is coming fast. And with a map of what the road should look like, you will easily tell the wall of water and debris from what you should be seeing.

The best reason the car might handle this however, is the very existence of this video, and the posts about it -- including this blog post here. The reason is that the developers of robocars, in order to test them, are busy building simulators. In these simulators they are programming every situation they can think of, even impossible situations, just to see what each revision of the car software will do. They are programming every situation that their cars have encountered on the road. Every situation that caused their software to make an error, or anybody else to make an error.

In other words, if you can think of it after a little bit of thinking, they probably thought of it too. And if it's in blog posts and famous news stories, they probably heard about it. Flooding and every kind of strange weather ever reported. The details of every accident from every police report that can be turned into a simulation. Earthquakes. Tornadoes. Hurricanes. Alien invasions. Oncoming tanks. If you can think of it without a major effort, and it seems like it could happen, they will put it in. And so every car will indeed be tested. In fact, the developers will probably have fun with the really strange situations which are so rare that they may not have commercial or safety justification, but still are interesting. Scenes from movies. James Bond car chases. You name it.

Not all at once, of course. Simulation programmers will prioritize and work on the most likely scenarios first. In time, they'll get to your strange one.

In this particular case, there is another thing to help with this situation. Tsunamis don't happen by surprise, not any more. The world, having seen them like this, now has earthquake detection and tsunami warning everywhere robocars are likely to go in the near future. The warnings will be transmitted along the same data stream warning cars about traffic, weather and road conditions. We even have maps of the terrain and can even predict what areas are low and which areas cars should head to in the event of a tsunami warning, and they will take routes designed to avoid risk. With superhuman knowledge, they will not panic and do much better than people at taking the route to high ground, and so they odds of them confronting the wall of water would be very slim, unless there was no choice. The robocar simply would not have been going down that road the way the Japanese driver was.

Now we get to a final special ability of robocars -- they will be just as capable in reverse gear as they are going forward, other than due to the speed limitations of reverse gear. So while you reverse timidly, a robocar need not do so. It will be able to pull off the fastest 3 point turn you can imagine if it wants to, or even just escape in reverse. Of course if it needs more speed than reverse offers, it would turn around in the best spot to do so. Stanford has even done a lot of research on drifting, and this will go into simulators too, so cars will probably know how to turn around as fast as a stunt driver if they have to. Electric cars may be able to go as fast in reverse as they can going forward to top it all off. (I should note that not all car designs feature sensors that see the same forward and back, so this may not be true for all vehicles, but all vehicles that can reverse at all need not be timid about it the way people are.)

So for this situation, and anything else we know about, robocars should do a superhuman job. That doesn't mean there aren't things nobody ever thought of. But the more videos and stories like this that get recorded, the less and less probable unknown events will be, and thus an unknown event where the software does the wrong thing becomes not impossible, but very low probability.


My first car was an automatic. 1965 buick skylark. It had two speeds forwards, and two speeds in reverse. So it could go as fast backwards as forwards, over 100mph, although stability suffered while turning in reverse.

This post made we wonder if there are sensors that can determine the composition of an obstacle based on its spectral signature (ie big blob of hydrogen and oxygen on the road mmmm I might be trying to cross a flooded causeway)?

Certainly sensors give you some clues on what things are. After all, you can usually tell with your eyes. Cameras and neural networks are actually getting pretty good at this. That changes at night, though.

LIDAR reflections and radar reflections also vary based on what they bounce off of. Smooth water is a bit harder to see in all sensors.

Cars with maps know the 3D shape of the road. If that changes they can know that. However, as noted, without extra info they will be conservative and stop. This GIF is an example of when that's wrong, a wall of water and debris coming at you. The "Stop and ask" strategy is a good one for most floods.

There is a decent chance the government will require that SDCs accept government OTA notifications of exclusion zones in case of natural disaster, security concerns, etc. All SDCs with passengers will be required to GTFO of the area, and unoccupied SDCs will be directed into the area to pick-up any population in need of evacuation.

In the case of Tsunami low-lying coastal areas will be defined as exclusion zones (long before the tsunami is actually scheduled to hit).

(BTW - the ability to define exclusion zones in real-time can be abused. Like any other power (e.g. no way to get by car to the anti-government rally). But there are definitely legitimate uses as well. This is one of the million new moral/legal/political issues arising from SDCs in particular and a digital society in general).

Cars should obey their owners, not the government. If you want to make a law for exclusion zones, it should apply, like all laws, to people, who then will control their technology according to the law, or choose to disobey, the right of free humans

In a similar vein how would it tell the difference between someone's garden bonfire blowing smoke across the road and a real forest fire. More mundanely, how would it handle blowing leaves?

As noted, the default for something in front of you is to slow down or stop, but these sorts of things (that you should not stop for) are one thing neural network systems will be good at classifying -- perhaps even better than humans soon. Same for birds (which you don't stop for) and some other animals. You can set your requirements high, so it every so often slows for a bird -- just as humans might -- as long as it never fails to stop for a baby or go around real debris.

If I was creating software for an autonomous car and suddenly all the sensors showed a huge wall of fast moving water, obviously, I'd do the correct thing and assume a massive sensor failure. I'm sure that the number and variety of crazy sensor failures will be more worth noting than the 1 in billions of people getting trapped by such a one of a kind freak event. Or if the car saw this kind of water maybe it would (usually rightly) assume it had accidently driven off a bridge and start unlocking/opening the doors/windows etc. This event is too rare to worry about.

General approaches might indeed make conservative choices unless what they see fits a reliable pattern.

But the point is, while you can never encounter everything, things that nobody has ever seen or thought of will be very rare. All the major disaster forms are not unknown things. And I would suspect you would also sit down and decide, "When do we need to back up really fast?" to build something that responds to stuff like this.

I think it's pretty likely that the car will have received notifications that flooding or tsunami or earthquake is likely. Yes, earthquake -- in Japan for example, people in Tokyo got many seconds warning on their computers that the earthquake was coming, and so will the cars in any place that is sane enough to have earthquake detectors. Even a few seconds warning can make a difference, and the cars will get it.

How can you stop a robotcar with weapons? What you need to hurt to a robotcar couldn't continue the movement under the control of AI?

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