Speed Limits and AI Self-Driving Cars


By Lance Eliot, the AI Trends Insider

I feel the need, the need for speed.

But, then again, some say that speed kills.

We have speed limits on our roadways, and I am sure there’ve been some days when you wished that there wasn’t any limit at all, so that you could get to that baseball game on-time or get home sooner after work. Other days you probably see some crazy drivers that seem to be speeding recklessly and you wish that there was a laser gun that would automatically zap those cars and prevent them from being dangerous scofflaws. Speed limits, love them and hate them, we seem to be conflicted anyway you look at it.

There are advocacy groups that say our existing speed limits are too high. They argue that we need to bring down the speed limits to slower and more “reasonable” speeds. On the other side of this coin, there are advocacy groups that say we need to raise the speed limits. Indeed, some of those advocating faster speeds are even prone to saying that we should not have any maximum speed limit at all. In a kind of capitalistic viewpoint, they argue that it should be a “free market” and allow anyone to drive as fast as they want. Having restrictions on our driving speed is akin to restricting our freedom of speech.

In the early days of the automobile, the UK is famous for having enacted one of the first laws to regulate driving speeds, doing so in 1832 in response to “furious driving” by some early adopters of these new horseless carriages. Supposedly, the first person actually convicted of the crime of speeding occurred in 1896 and the driver was going an outrageously dangerous 8 miles per hour. Of course, as cars modernized, and as they became widespread, there gradually was a progressively increasing speed limit established. It kept going up, until the advent of the oil crisis led to a backlash against gas guzzling cars that seemed to consume too much gas after they exceeded a speed of around 55 miles per hour.

Nowadays, there are those that argue that the gas consumption curves of years ago are no longer applicable to the fuel efficiencies of modern day gas powered cars. They say that the fuel efficiency once used to set speed limits is woefully outdated. Furthermore, we are seeing more cars becoming electrically powered and the question is raised as to whether the gas fuel charts make any sense when our cars are powered instead by electricity. Those that concede the battery powered cars will change things are though quick to point out that there’s at best 1% of all cars in the US that are electrically powered, and so they say come back and talk with them about speed limits when the other 99% of the gasoline gulping cars on the roadway become electrical.

The argument about fuel efficiencies is just one of the factors that goes into ascertaining speed limits. Yes, it is perhaps one of the most discussed topics and the 600-pound gorilla in the debate room, but there are other factors that get onto the table too.

Here’s some factors that are used as arguing for setting speed limits:

  •         Can reduce roadway casualties due to car accidents and collisions that happen when going fast
  •         Can lessen the physical impact to our roadways that makes the roads spotty and full of potholes
  •         Can improve our air quality by reducing the amount of exhaust pollutants that occur when going fast
  •         Can make our roadways safer for non-car traffic such as bicyclists and pedestrians
  •         And can presumably be more fuel efficient (had to list it)

Each of those factors are readily open to discussion and debate. For example, advances in cars have dramatically lessened the amount of pollutants generated and some assert that there’s a marginal indication that faster speeds also produce any significantly larger amount of air pollutants. In terms of roadways getting chopped up by going fast, some would say that with the improvements in tires and if the roads were paved the right way to begin with, there’s little evidence that going faster is going to disproportionately tear up our roads.

For those of you that crave speed, you’ve likely gone to Germany to drive on the autobahns. There are many stretches of the autobahn that have no designated speed limit, or that offer an “advisory” speed limit but that you can choose to ignore if you wish. I remember when I lived in Frankfurt that I was astonished to be able to drive nearly as fast as I had the guts to push down on the accelerator pedal, and it made many of my long-distance driving trips on the autobahn both exciting and also terrifying. Unless you’ve been driving NASCAR race cars for a living, finding yourself driving at extremely high speeds is not for the faint of heart. I found that when I exited the autobahn, I was often bathed in sweat and my hands had been gripping the steering wheel in a near-death-like manner.

Like most states in the United States, California has a so-called “basic speed law” that refers to the notion that you are supposed to drive as a “reasonable man” would drive (the word “man” here is meant to indicate mankind, as in both men and women). You are not supposed to drive faster than is safe for whatever the current roadway conditions are.

Why My Friend Got a Speeding Ticket for Going 55 mph

I mention this because a good friend got a speeding ticket for driving 55 miles per hour on Pacific Coast Highway (PCH), which had a posted speed limit of 55 mph, and he was really upset. I asked him why a Highway Patrol officer would give him a ticket for doing the speed limit, and at first my friend said that they were just out to get him. Upon further inquiry, my friend eventually revealed that the stretch of the PCH had heavy fog at the time he was driving it, and it was soaking wet and partially flooded from recent rains. The officer told him that he was driving at an unsafe speed for the traffic conditions.

In short, the speed limit signs are intended for ideal driving conditions. Of course, the reality is that many people seem to think that these signs are merely advisory, and so they go much faster than what the signs say. One driver that I know well has told me several times that she perceives the speed limit signs as the minimum speed you should drive (this is a combination of humor and a bit of reality for her too). Some drivers see the speed limit signs as a kind of game – how much faster can they go, without getting caught. They are proud to report that they went 55 mph in a 25 mph zone and then challenge their friends to see if they can top it.

It’s a matter of physics that the faster you go, the longer it’s going to take to come to a halt. The stopping distances get larger at higher speeds. This is an important point because drivers tend to not take into consideration that as they reach higher speeds they are reducing their chances of stopping on a dime. Whatever they thought they could do at lower speeds is not the same at the higher speeds. Human drivers are notorious for misjudging stopping distances. They don’t automatically recalibrate in their minds the nature of the higher speeds and the amount of true stopping distance they will need.

Since mankind can be kind of irrational about their driving speeds, mankind has equally come up with ways to try and make those irrational drivers become more rational. Besides the threat of getting a speeding ticket, there are additional methods of putting a rein on speeders. Traffic calming is one such technique. This refers to putting in place roadway obstacles or shaping the roads to try and prevent or at least mitigate the chances of speeding.

I’m sure you’ve driven in an area that has speed bumps on the roadway. Perhaps you’ve seen them near a school ground or in a parking lot. These physical humps are there to shake the teeth of the speeding driver and get them to slow down. It can be quite jarring to try and speed over a speed bump. When I see some nut trying to do so, I wait and watch, hopeful that I’ll see their transmission drop out of the bottom of their car or maybe see the entire underbelly of the car become wrecked and disable the car for further movement. That’s just my dream.

Another approach to traffic calming involves designing the roadway for slowing down traffic. Sometimes a street will be narrowed to force the flow of traffic into a single lane, which then ultimately slows down the overall traffic on that roadway. There was an effort here in SoCal to slow down a highly trafficked area by putting in an expanded bike lane. This seemed to be a good idea. It would make more space for bicyclists and encourage non-car options of transportation, and it would make the prevailing traffic move at a slower and safer pace.

One area that tried this had a pretty vigorously negative reaction by drivers. Their daily commute to work doubled or tripled. Also, cars opted to avoid the congestion on the main road and began to flood into the nearby neighborhoods, causing danger to children. Some contended that this was causing their property values to plummet. Local merchants said that their business was dropping because word spread that it was impossible to drive to their businesses to go shopping. The area was also a tourist spot, and tourism dried up, which then also caused businesses to lose more business. And so on.

Another solution involves using speed limiters on cars. You’ve likely not seen this. A speed limiter is either a device or software that will prevent a car from going above a certain speed. The simplest versions of a speed limiter are only focused on a maximum speed limit. It might for example be set to 70 miles per hour, and thus even if your car can go faster, the device won’t let your car do so. It essentially bypasses your pressing on the accelerator pedal. With modern cars, you don’t necessarily need a physical device to do this, and instead the software that regulates the acceleration of the car can be set with a limit.

More complex versions of the speed limiter allow for a multitude of settings. For example, there might be a setting that establishes a maximum speed for the car during daylight, and a different speed limit for nighttime driving. Currently, those limiters are relatively crude and can’t do much in terms of being sophisticated about setting the speed limits. Also, it usually requires that you take your car into a dealership or someplace where they can put in place the limiter. The consumer has only a limited ability to tinker with the speed limiter.

I’ve seen some parents that did this on their cars for their children. The logic was that the teenage driver would be safer if they didn’t drive more than the allowed speed limit. Some parents even insist that their teenage driver put an app on their smartphone that will keep track of movement, such that the app will know when the teenager is going more than walking speed. The app then reports to the parent as to how fast the teenager was going, including not only when driving a car but also when being an occupant in someone else’s car (got to curtail those joy riding with friend’s experiences!). As you can imagine, the teenagers aren’t thrilled about this form of Big Brother tracking.

One of the criticisms of the speed limiters is that it might cause a restriction when you want to overcome the restriction. Suppose that you are driving your car and it has a speed limiter set to 55 mph. A rock flies off an overpass and smashes through the windshield and strikes your front seat passenger. You decide that you need to rush to the hospital to save the passenger. But, the limiter prevents you from doing so. Bad news!  By the way, this actually happened recently that a rock flew through a windshield, hitting the husband while his wife was driving the car. She had the presence of mind to drive him to a hospital. I realize that you might say that this is an unfair rare example and that by-and-large there would be few valid exceptions to the speed limiter – yes, that’s fine, but I can also say that when you need the exception, and even if rare, it could be a life killer.

One very rational criticism about going fast is that it really doesn’t save you much time. For example, it has been pointed out that if you went at a speed of 80 mph for a 50-mile trip, and did so rather than going 75 mph, you would only save about 2 ½ minutes for the overall trip. Indeed, I’ve seen cars pass me on the main freeway between Los Angeles and San Francisco that were going at least 90 mph, and yet I often catch-up with them at a roadside gas station, and they are lazily getting gas and stocking up on provisions at the mini-mart. The time they spent at this stop would readily use up any time they had “saved” by speeding far beyond the speed limit. It’s not as though they were doing a race car type of pit stop with strict timing to get back right away onto the road. Their having sped seems senseless.

This few minutes’ difference though could be a significance difference when driving even short distances, depending upon an emergency situation.  For the wife that was driving her husband to the hospital, speeding could make the difference of his getting to the hospital in time to be saved. A counter-argument is that the panic driving of the wife and her speeding could actually cause other car accidents and maybe harm or injure others, while in her quest to have her husband saved.

In some areas of the country, the speed limit is established by first measuring the prevalent speed based on 85% of the traffic that flows on the given road. Based on that number, the speed limit is set within about 5 miles per hour of that overall average. This assumes that the final tabulation does not exceed a federally mandated cap or other caps in that jurisdiction. For many, they like the idea that the speed limit should be set by how people actually drive in an area, rather than as determined by a governmental body that regulates the use of the roads.

AI Self-Driving Cars Need to be Savvy About Speed Limits

What does this have to do with AI self-driving cars?

At the Cybernetic Self-Driving Car Institute, we are developing AI systems for self-driving cars and this includes being savvy about speed limits.

Let’s consider some of the ramifications about speed limits and self-driving cars.

Those that believe in a utopian world of all self-driving cars, which I claim won’t happen for a very long time since we currently have 200+ million conventional cars in the US and those aren’t going away overnight, but anyway once someday that we do have all self-driving cars that then we can do something about our speed limits. I say this because suppose we take the human out of the equation for why we set speed limits.

If you assume that the human won’t be driving any cars on our roadways, we no longer need to be concerned about a human drunk driver. If we also assume that the AI will be able to drive the car as well as or even better than a human proper driver, we will presumably have many less car accidents. For those that falsely believe we will end-up with zero accidents, I point out that there will still be accidents involving cars that hit debris in the roadway, or that blow out a tire and veer into another lane, or that hit a pedestrian that steps onto the roadway unexpectedly, and so on. We aren’t going to have zero fatalities, and I’d ask that people stop claiming that it will happen.

So, given the aforementioned caveats, in theory we could increase the speed limits since we no longer have the human frailties of driving.

What about the other factors that we had covered earlier?

It was suggested that higher speeds harm the roadways in terms of physical impacts to the roadway. There’s nothing magical about self-driving cars that will overcome this. Now, as mentioned, cars are getting better in terms of their design and so generally a better designed car, conventional or self-driving, will nonetheless extract less of a toll on the physical roadways.

In terms of improving air quality, again a self-driving car doesn’t really impact this aspect per se, and it’s up to how the car is designed that will make a difference, conventional or self-driving. Same generally goes for the topic of fuel efficiency. The point being that even if a self-driving car is a better driver than a human, going at high speeds will still produce the same amount of pollutants and be as fuel inefficient as if a human driver was driving, and so we would need to decide how important those factors are (having taken off the table the human driver frailties).

This brings us to the factor that our roadways would be safer at lower speeds due to the greater chance of avoiding non-car traffic accidents such as with bicyclists and pedestrians. The question then is whether an AI self-driving car, if allowed to go at speeds faster than our existing speed limits, would it have a tendency to be able to avoid these non-car traffic accidents, doing so at a better rate than if it were a human driver?

You might say that the AI system would hopefully be less likely than humans to get into these non-car accidents. This is based on the assumption of human frailties, namely that humans are apt to be sleepy when driving and fail to see a pedestrian, or be drunk, or otherwise not be as “flawless” as a machine would be. But, we need to be careful in assuming that the AI and the sensors of the self-driving car are of necessity more astute than a human driver and their human senses and human mind. It’s a science fiction type of assumption that the AI and the sensors will work flawlessly, all of the time, and in every way.

In fact, it is unlikely that the AI and the sensors will be perfect machines. The sensors will at times falter and be unable to detect pedestrians and bicyclists. The sensors can fail entirely and the AI is left with a myopic understanding of the surroundings. Some of you will say that the odds of the sensors faltering or failing are miniscule and that I am misleading you about their error rates. Well, keep in mind that if we assume that all 200 million cars in the US alone are replaced ultimately with self-driving cars, and all of those self-driving cars have some X number of sensors, perhaps two dozen or more, and that those will fail or falter on some kind of probability basis, you are now looking at something that will happen in the large rather than in the small

Does it make sense to increase the speed limit in a world of self-driving cars?

We are going to have a mixture of human driven cars and self-driving cars for many decades, and so if we do increase the speed limit it would imply that human drivers could go faster too. In that case, we’re back to the frailties of human drivers and what happens when they are allowed to drive faster. Some say that we could devote lanes to self-driving cars, and separate the human drivers from the self-driving cars. Imagine if you are driving on the freeway, and the HOV lane is reserved for self-driving cars. And, suppose further that those self-driving cars are allowed to go at a speed of 100 mph, or maybe at whatever speed they can go.

This could be a dangerous situation. Human drivers might veer into this special lane and cause a wreck. When self-driving cars try to get into the lane, it will be hard for them to reach the prevailing speeds in that lane as when coming from the conventional speed lanes. When self-driving cars exit from this special lane, they will be going at a much higher speed than the rest of the traffic. Overall, it could be a disastrous approach.  Some might say that we just need to block off the special lanes and not allow any mixing with the human driven cars. Yes, this would help the circumstance, but it also would require a rather costly change to our roadway infrastructure, which maybe makes economic sense or maybe not.

I realize that an all self-driving car situation would allow for the self-driving cars to coordinate their efforts. Using V2V (vehicle-to-vehicle communications), the self-driving cars could let each other know when a self-driving car wants to get into a lane or exit from a lane. The other nearby self-driving cars would then be aware to allow for this movement of the other self-driving car. In that manner, it could be that we would not have any speed limit at all. The AI’s of the self-driving cars would just agree to whatever speed seems to make sense for the prevailing situation.

This brings up too that the AI of the self-driving car can be a kind of speed limiter. The AI is going to decide what speed to go. Should it be programmed to never go faster than a set speed limit?

You could contend that AI self-driving cars will always be law abiding. They will always obey the speed limit. Assuming that the AI is indeed programmed for this, and that it works flawlessly in doing so, we are back to our earlier question about whether the speed limit should always apply or not, such as the case of the wife driving her husband to the hospital. If you were in a self-driving car, and your husband was bleeding and dying, and if the AI refused to go faster than the posted speed limit, would you be upset that the AI won’t do your bidding and go faster?

If the AI is really sharp, it might be able to dialogue with the occupants and figure out that an emergency is taking place. Perhaps, in that case, the AI would have been pre-programmed that it can go as fast as it can achieve. This kind of notion though is a bit far-fetched and we’d likely need to still have some means of validating that the AI is doing the right thing, maybe an after-the-fact kind of verification. This also brings up whether all self-driving cars will be doing this in the same manner. If we have one auto maker make their self-driving car AI do one thing, and another do something else, in terms of speed limits, we’re bound to have quite a mess.

Perhaps we should have a governmental regulation that indicates how the self-driving cars and their AI is to behave with regard to speed limits. Some would argue to keep the government out of such things, and instead maybe there should be an industry-based association that can set standards for this type of aspect. Others might say that the marketplace should decide, and leave it to each auto maker to provide whatever they believe the market most wants.

Speed limits can presumably become digitally-based in the future. We could still have posted speed limit signs, but they would be a digital display rather than a painted sign. This would allow for the speed limit to be changed at any time, as based on the time of day, the prevailing traffic conditions and so on. For an AI self-driving car, it could “read” the digital sign by using a camera sensor that’s on the self-driving car. Or, the digital sign could emit a signal that transmits the posted speed limit.

If we did have all self-driving cars, we could do away with the speed limit signs altogether. In theory, the speed limit could be a virtual speed limit and the use of V2I (vehicle-to-infrastructure) system would communicate the speed limit to the self-driving cars. As self-driving cars drive down a particular street, the V2I lets them know that since it a road next to a school and since it is morning time when the kids are arriving, the speed limit is 5 mph.  Once the kids are in the classrooms, the V2I communicates to any passing self-driving cars that the speed limit has been raised to 15 mph. And so on.

We might allow for AI self-driving cars to exceed the speed limit when there’s an emergency, and maybe even when there isn’t an emergency. Suppose we as a society decide that you can go faster than the speed limit, but you need to pay to do so. It’s almost like a toll. Rather than paying a speeding ticket after you’ve speeded, this would be a pre-payment so that you could speed. Your AI self-driving car might use the V2I to make a request to exceed the speed limit, the V2I system decides the request is valid, charges on-line to the self-driving car owner, and then grants permission to the AI of the self-driving car to go ahead and speed. This though could also be perceived as elitist and allow the wealthy to readily speed while the poor would be relegated to the slow zone for AI self-driving cars.

Would we still need any traffic-calming capabilities in an all self-driving car world? This depends upon whether the self-driving car are able to communicate with the V2I. If there isn’t an appropriate V2I, we might still need the speed bumps since otherwise the AI won’t know that it should necessarily be going slowly in a parking lot. In terms of speed limiters, imagine that if we as a society wanted to suddenly make the entire country be a 35 mph maximum speed limit, in theory something could be broadcast to all AI self-driving cars that essentially instantaneously set the speed limit to 35.

This though assumes that all self-driving cars will be able to communicate with some kind of overarching governing system. We don’t have that as yet. Will we want this? Some would say it makes sense to have an ability to access all self-driving cars at once, while others would say this bodes for dangerous times, such as if a hacker was able to suddenly make all self-driving cars throughout the country come to a halt (such as setting a speed limit of zero), doing so all at once.

Now that you’ve had a chance to think about the nature of speed limits, it hopefully has raised your overall awareness that it is not such an easy answer as to whether with AI self-driving cars we should have higher speed limits, or possibly even no speed limits at all. I would also urge you to realize that the day when we have all self-driving cars and no human driven cars is a long, long, long ways in the future. As such, whatever we want to do about speed limits, it will need to be undertaken in a world consisting of both human drivers and AI self-driving cars.

Maybe we’d have AI that when stopped by a police officer and asked whether it saw the speed limit sign, the AI would respond by saying yes, but it doesn’t believe everything it reads.  Drum roll please and ba-dum-bum-ching.

This content is originally posted on AI Trends.