No, cars won't circle around in traffic to avoid paying for parking


For many years, people have wondered if people might tell their robocars to just drive continuously around the block rather than pay for parking. I've written before about how that doesn't make sense, but a recent paper from Adam Millard-Ball of UC Santa Cruz tries to make a real case that it could make economic sense, even if it's antisocial.

Stanford showed off robocar valet parking in 2009

I think the paper makes 4 errors, any of which are enough to eliminate the problem.

  1. He believes a car could drive super slowly (less than 2mph net speed.) That's illegal and challenging
  2. He believes a car going that slowly would incur costs less than 50 cents per hour of operation. It's probably quite a bit more.
  3. He does not account for how the cost of parking a robocar will be much less than parking a regular car -- possibly even less than the 50 cents/hour he estimates
  4. He does not account for how it's much easier to make things illegal in a robocar, because you enforce on a dozen companies, not on a million drivers.

I've written up a more detailed analysis of the issues here and published it in a new article. Read

No, cars won't circle around in traffic to avoid paying for parking


Yeah, I'm sure it'll be illegal for a car to drive around at 2 miles per hour in lieu of parking. If there's enough room on the roads to let people do this, they'll just let them park on the roads.

That said, when calculating the cost of parking, you need to make sure to factor in the cost to drive to the parking location (and to switch parking locations, if you're parking in one of the cheapo we-can-kick-you-out places.

My expectation is that the algorithms will get clever in deciding where to park and how to pay the best price overall, including when you have to move. Ideally, you would want your car to go a couple miles out of the CBD for super cheap, then move in half an hour before you want to leave. Problem is, everybody wants the same thing, so that half hour might be quite expensive. On the plus side, the path into town is not usually congested.

Those who pay a bit extra will get that nearby parking for the last half hour so they don't have to summon 10 minutes in advance.

Not sure the path into town not being congested is a plus. The more congested it is, the less time you need to pay for parking. :D

In fact, you probably want to choose the path (among reasonably similar-distance ones) that is the slowest.

It depends on how much it's costing per hour to have your car out on the street in motion. If parking is 50 cents/hour (which I think it will be less than) then no, you don't want the slowest route, you want the fastest, so you don't have to summon very far in advance.

In most cases I don't expect to be actively summoning at all for my ride home from work. It's going to be about the same time every day, so the car will be free to take the slowest route, unless for some reason I summon it to leave early.

If I know the car needs to pick me up at 5:00, and it can choose between a route that takes a hour (factoring in traffic, leaving at 4:00) and goes X miles or a route that takes 30 minutes (factoring in traffic, leaving at 4:30) and goes X+1 miles, and parking is 50 cents/hour, and driving is less than 50 cents/mile, then it should take the slower route.

Another advantage of the slower route is that it can adjust to a faster route if there's more traffic than it expected, whereas if it takes the fastest route from the start and there's unexpected traffic, then it's going to be late.

While I still doubt this is the wisest thing to do, if it turns out that the cost of operating the car is so low that this makes economic sense, and people start doing it, then it will very likely get prohibited.

Depending on what is meant by "slower route" of course. If the route is naturally slower, that will be fine. If the route is slower because of congestion, less so. Many routes you think of as naturally slower are actually due to implied congestion, because things like traffic lights and stop signs are there because of the presence of traffic, vehicles are yielding to other vehicles, slowing them down.

We will have to find out if slow driving is cheap or not. The truth is I don't think we know.

It also depends where you are directing the car to pick you up. If it's a congested pick-up spot, we don't want you arriving early, nor do we want you gumming up the road delaying your arrival.

But yes, there will be desire for timed arrival (a must for reserved pick-up windows.) So the problem is tough.

Of course, one solution is much more road management, so there is no congestion. I have written a bunch about plans for this. It's a simpler but more extreme form of congestion charging -- where you don't let more cars on the road than it can handle, and thus don't get much congestion. In that world you get very predictable travel times, which is very good for many things.

Surely there are situations where one can take a slower route that is actually less distance. In fact, sometimes you can take a slower route that is less distance *and* more energy efficient. Ideally a car (or perhaps some external software that tells the car what route to take) will take that into consideration too when planning out the optimal route.

I'm not sure you can (or should) outright prohibit this sort of thing. In some cases you can ban through traffic, but that's hard to enforce. If a route is getting too congested, then charging for road usage might make sense (it might make sense anyway as cars move from gasoline to electricity). That won't prohibit taking the slower route in all situations, but it'll be another factor to consider, as road usage fees will probably be higher on more congested routes. It might also make sense to charge higher fees for unmanned vehicles.

In the longer term, driverless vehicles might help us move away from public roadways altogether, and toward privately owned roads. That's the only real way to solve the tragedy of the commons that causes roadway congestion.

Yes, I don't think you would prohibit it outright. Mostly I would look into it if it became clear that it was causing a problem.

It probably won't because major carmakers aren't going to put in a "deliberately waste time" mode. But they will put in modes that do what customers want that aren't clearly antisocial.

I believe that the roads should never have been a commons though, we pay a high price for them being that way, and so I expect more road management is coming. There are many proposals, including congestion charging where you are charged per square-foot-second of congested road you use, which would encourage fastest and least congested roads. And metering proposals, and cordon proposals etc.

Millard-Ball is a fan of congestion charging, and it has its merits. He worries about cheap parking, saying that in effect, expensive parking is the closest thing the world has to congestion charging. Parking downtown is expensive enough to keep cars away, reducing traffic.

It's not really a "deliberately waste time" mode. It's just calculating all the costs of traveling.

I'd very much expect car companies to do this, if they didn't provide an API. If the car is going to decide where to park and for how long, then it needs to be able to choose that in a way that minimizes costs. It makes absolutely zero sense for the car to speed along the highway at 75 miles per hour when it could leave earlier, travel at an average of 25 on lower speed, more congested roads, save energy, *and* save parking fees. It's not wasting time at all. It's saving time, it's saving energy, and it'd even be making the world *less* congested if it weren't for the fact that roads are managed by governments instead of the free market. (After all, parking is its own form of congestion.)

If they're not going to provide an API to decide when to park and what routes to take, then not factoring in the full costs of these decisions is a very annoying bug. I very much expect car companies to provide an API for non-safety-critical things like navigation, though.

I somewhat agree that roads should never have been a commons. They should have always been privately owned. Whether or not the owner should have given unlimited free access to the public or not depends on the road. For *many* roads this makes perfect sense. At least, it makes perfect sense in the absence of self-driving vehicles. Once self-driving vehicles become cheap enough, we might have to have access restrictions on nearly all roads, lest we be bombarded with advertising vehicles and autonomous ice-cream vendors and all the other crazy things that we'll see popping up once it becomes cost-effective to "spam" the roads.

The private cars will of course want to best serve their owners, and save their owner's money. However, they will also not want to let their owners be deliberately antisocial, because the company will get criticised for that, and may even get legal pressure to remove such functions. So they will be hesitant about putting them in.

The difference is, they need permission from the governments to operate on the roads, and so they have to please them. At least from the state and federal governments, but possibly the cities too. Programs like waze do not need any government's permission just to exist, and so they can include things like cop spotting, and directing people down small residential streets to avoid traffic.

So the governments are going to say to car vendors, "You want to run your cars on our streets, don't put in features that go against social goals." That's going to be a general rule, without even the need for specific rules. They will sometimes fight in courts, I bet, when governments ask for too much. But they won't fight cases that they don't look good on. Anything that's making traffic worse just to save a few pennies will not look good.

So I think we'll end up at a balance on how a car drives to pick people up. It will be OK to take a slower route to be more energy efficient. Energy efficient is another social goal. Going slower than traffic will not be OK. Going down quiet streets will probably get a backlash -- it already does with Waze.

As I suggested before, all they have to do is offer an API. There will be limits as to what one can do, even through the API, but things that are safe and legal probably should be allowed.

If certain things are too antisocial they can be made illegal. Banning unmanned vehicles from quiet residential streets, except when that neighborhood is the origin or destination, might be a good law to pass.

Going slower than traffic while driving in the slow lane should probably remain legal. But by that I don't mean going 2 miles an hour. Something reasonable will have to be worked out by legislatures, but it's not very long ago that 55 miles per hour was the highest speed limit virtually anywhere in the USA. I don't think you should be able to force people to go 75.

I'll probably tune my speed down on my self-driving vehicle even when I'm in it most times. With the ability to do work when I'm traveling the need for speed will go way down. Hopefully the law will accommodate people like me. You can call me antisocial, but I think the ones being antisocial are the ones trying to force their preferred speed on others.

Going so slow as to impede traffic is already illegal in California and many other places.

There will be an API. The API probably won't have a "take the slow route" and it might not even have the ability for you to select the route when unmanned. You could hack around that, by constantly giving it new destinations to effectively pick the route, but the API would certainly notice you were doing that, if it was desired to prevent that.

"Going so slow as to impede traffic" is not the same, in my opinion, as "Going slower than traffic," particularly on a multi-lane road. Also, interestingly, most states also have adopted DoT regulations of low speed vehicles and neighborhood electric vehicles that exempt such vehicles from "slow speed impeding traffic" laws. For some people an autonomous golf cart (or something like it)) might be the best way to commute to and from work.

But there are limits. NEVs are limited to low speed roads and have other restrictions. And they are given this exception because they have other social benefits, low emissions and small parking size.

It's odd how you figure that the government can't say "boo" to Waze providing cop warnings and directing traffic down streets not built for it, but that the government can totally stop you driving your car really slowly rather than parking it.

You're right that VC 22400 is often used to cite Uber drivers who've stopped in a no-parking zone to wait for a pickup, but the solution to that is to not be stopped.

It is interesting how different these are, though owned by the same company.

Waze is an app, and nothing more. It shares information (which has 1st amendment protection) and it needs no permission to exist. By default, it can exist, it would take a special law to try to stop it from doing something, and that might be unconstitutional.

Waymo is a service, not an app. It needs permission from the government before it can drive mile one. Its vehicles need licences and certifications. If it puts in an antisocial behaviour or illegal behaviour like driving too slow, the governments can shut it down in a heartbeat.

Perhaps odd, but that's how it is.

You're assuming that city governments won't *love* the idea of vehicles whose speed is restricted to 2 mph. It's pretty hard (although not impossible) to kill a pedestrian with a car moving at only 2 mph that stops as soon as it touches someone.

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