Self-driving cars will cause sprawl | Hacker News Reader

Self-driving cars will cause sprawl

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51 pointsaresant65 comments

I'm probably dim. But I fail to understand why self driving cars will make the congestions in morning and evening commutes be radically reduced.

If the wall described in the article is to be pushed out, the speed must increase from today.

If we can go to work and go home at more varying times over a day then yes congestion should decrease. But why would AVs cause that effect? As long as everybody is expected to be at the office at 8am and leave at about 5pm, we need to move the same amount of people back and forth at the same time. Ride sharing (hey buses and metros are efficient for that!) may make the number of vehicles/person go down.

The amount of vehicles a road can handle before becoming congested is dependent on the safe distance needed between cars at a particular speed, the reaction time of drivers, and the consistency and coordination of driving styles.

You won't see any improvements from AVs until human drivers are banned, after which the AVs can all drive at 100 mph and inches apart from each other. Traffic lights would also no longer be necessary.

You would also have to ban pedestrians and cyclists.

It's not viable in cities, but large parts of commutes and congestion are on freeways where they are banned anyway. We don't even want cars driving 100 mph in cities because of noise and pollution (for gasoline cars).

And if we went fully AV, we could still do away with traffic lights for cars in cities, as long as pedestrians and cyclists have their own safe passages and/or AVs are smart enough to deal with them just crossing at will.

And you shouldn't care about noise anymore. When there's a constant stream of self-driving cars at 100 mph on the streets every single place in the city will sound like living next to a major highway.

And no, electric engines won't solve this problem, at speeds above 30 mph the engine is no longer the major source of noise, it's the tires and the aerodynamic noise.

> AVs can all drive at 100 mph and inches apart from each other

Hard to see how this could ever go wrong isn't it

>You won't see any improvements from AVs until human drivers are banned

Automatically re-routing traffic when the roads start being congested already works before that and it'll help a lot.

Soon mankind will realize that it is better to spend one dollar and remove all ads rather than imposing major annoyance in the hope of gaining 5 cents.

Is human reaction time is the only reason for enforcing safe driving distance?

Even if AI increases to great levels, inertia still would exist. A large truck cannot stop in inches when traveling at 100 mph.

It only has to stop as quickly as the truck in front.

But the truck in front busted a tire... Now what? If the distance between vehicles is 1cm,then literally thousands of vehicles will crash.

The AVs could offer some advantages (ie cheap car sharing via resource pooling, reduced parking space requirements in urban centers) but safety or speed aren't part of the deal. AI isn't superhuman and AVs aren't able to brake the rules of physics.

An interesting thing about objects is that they can move in three dimensions.

All you need is an object of any kind, including a downed tree limb or falling rock, entering the stream of vehicles at an angle, to cause cataclysmic disaster in this scenario.

what if the vehicle in front is a small car?

Human reaction time would be a reason for additional distance beyond what is needed to stop, but agreed, I don't see the distance to be reduced that much. Reducing the distance to virtually nil is going to cause a crash at the first slope as well.

If the reliability is high enough then the low rate of accidents is worth the risk. Other modes of transport are able to operate at small margins due to high reliability requirements.

You forgot the most important factor: the exits. If the exits are congested because capacity is lower near the destination, there's nothing you can do in the road.

And most jams are caused exactly by this.

after which the AVs can all drive at 100 mph and inches apart from each other

Except... it's likely that people won't own AVs of their own, so we'll be captive passengers inside a corporation's AV. That's a prime advertising opportunity. Why have an AV that gets people from A to B as quickly as possible when you can go at 55mph without needing to change the law and get double the time with the passenger?

Good point, though I suppose it would be a battle between corps that need productive time from their employees rather than time watching ads in a car. I guess if the time is stolen from personal time rather than work time then all good.

Traffic lights would also no longer be necessary

How will pedestrians know when to cross the road? Will bicycles also become illegal?

They won't, it's something AV proponents love to claim though.

The claim is that cars will be able to drive closer at higher speeds or something. But, 2 tons of steel is still a deadly weapon no matter who's driving it. A car can still suffer a(n unpredictable) blowout or mechanics failure, malicious people can still screw with traffic, roads and infrastructure will still be poorly funded, and even wildlife (deer specifically) still exist.

Any of these things will cause huge problems to cars travelling too close together. That's even ignoring the fact that traffic going inbound to dense urban centers is limited by the infrastructure of the city and layout of those roads, parking garages, and businesses- not the speed at which people can travel closely on the road.

By the time we get level 5 autonomous vehicles, we'll have robots performing most minimum wage jobs (picking crops, making coffee and hamburgers, retail) and culture will probably have shifted to a remote-work-friendly mindset. The fact that there just won't be that many jobs for people to work will reduce traffic more than AVs will "because they can go faster".

Numberphile had a recent video on car crashes here: https://www.youtube.com/watch?v=i3D7XYQExt0

In short: Since kinetic energy goes as (velocity)^2, doubling the speed will quadruple the stopping distance (MANY other factors are significant, this is a rough estimate). 3X of the speed is ~9X the stopping distance, etc.

NHTSB guidelines for 'proper' following distance are nearly never seen in LA and NYC, it's typically much shorter. If anything, L5 AVs will probably have longer gaps between AVs than what is currently on the road. Likely, the major improvement of L5 AVs will be in safety, not congestion. It turns out (I think), you can't technology your way out of a political problem. We need higher density housing, not magic carpets (effectively).

We need cities that are easily traversed by humans, not cars.

They need to be really small for that to work, and what's happening is that only 1M+ or even 5M+ population areas are in demand.

A home to 5M people isn't likely going to be very walkable.

> They need to be really small for that to work

That's not true. One solution is the '10 Minute City/Neighborhood' and its guide to decision-making.

You can have locally village-like situations in a large city if you have a high enough population density and then connect these local villages with mass transit. I can walk to three movie theatres, all doctors, a university hospital, five or six different supermarkets and a shitload of other shops despite living in an agglomeration of three million. Another similar area is just six stops on the subway away.

Yes, that’s how Tokyo works. Living standard with average salary is quite nice for this reason.

The need to be small geographically. Manhattan is very walkable, and very in demand.

Add good bicycle infrastructure and it's a lot more doable.

Most large European cities are very walkable. London, Paris or Berlin are really walkable and host millions of people. On the contrary, with the exception of North America, larger cities are usually more walkable than small settlements and rural places.

I'm not really sure they're so walkable. You can probably walk your local borough, dissected by highways and rail. There's not much happening on it, and it quickly becomes repetitive. This unless you live in urban core, which is contiguous but expensive so that it needs the outskirts to maintain its buzz.

Citation massively needed. Plenty of folks walk in cities with more than 5M people (London comes to mind). It's not like you routinely visit every last business in that city.

Also, if you have a bicycle and decent bike network you can traverse an entire major city in 45 - 60 minutes. The problem is that most new cities are virtually nothing but asphalt and empty land in order to accommodate cars. I am sometimes called weird for saying this - but seriously - look at pictures taken at elevation and a modern "city" looks very sparse indeed.

This is how SF-style housing crises are made. When you force everyone to be very geographically close to their place of employment, it has the dual effects of reducing the effective supply of available housing options, while simultaneously increasing demand for housing in a very specific geographic area. If you look at the cities that have done this, both in the US and abroad, you will notice that their rents are typically astronomical.

SF has the issue that certain popular types of work are only available in SF, and if someone wants to be in that type of work, they have very few options for where to live.

More, smaller cities - or even large cities with multiple “city centres” - and an approach which attempts to ensure that the SF centralisation of the consumer tech industry couldn’t be a thing, would be the solution, surely, if you decided to design from top-down?

No, the point is that the Bay Area is too congested (and to some extent intentionally congested) to allow for an appreciable amount of commuting. One person's sprawl is another person's affordable housing.

The point is that the Bay Area is essentially the unique place where you have to work if you want to work in the consumer tech industry on things that make newspaper headlines. The point is that if people could work on that in more places, the problem of wanting to commute to a specific area wouldn't exist.

While that may be true, it's also passing the buck since there are a lot of economically productive cities where commuting is practical and rents are cheap.

Honestly speaking - the concept of nearly every person in America commuting by car into work, home, and then having to get back in the car to go to any sort of entertainment, is something to solve on its own. "Let's have people commuting more into SF so we can keep building suburbs empty of anything to do" seems a bizarre solution to the problem of SF being a hotspot for work. American commutes are getting longer every year as it is, and hour-long commutes by car are becoming more and more of a thing for more and more people. And this might be on top of a school run before work!

In the affordable housing I've lived in, we had malls, parks, cinemas, skate parks, all within walking distance. Pedestrian bridges over any busy roads so you could take your young children everywhere they'd need to go without hopping in a car. The result of the social housing boom of the last century in the UK. Work might be somewhere else, but you'd take a bus or a train there, depending on what city you live in. It's unlikely that there'd be staff parking where you work, anyway, unless you worked at an office on the edge of town, even if you had space for a car at home.

The problem with San Francisco is that it's pathologically unable to build apartment buildings.

But that wouldn't be an issue if you could just commute from somewhere else.

That's also how NYC-style housing crises are made, they have 27k people per square mile.

All will depend on whether people will still feel being chauffeured around in a self driving vehicle as 'travel time'. With few restrictions, you can design an autonomous light truck to be like a true 'mobile home-office/bedroom/apartment'. My personal prediction is that when we get to true AV's, it will be an ecological disaster, clogging roads orders of magnitude more than today.

Thought experiment to help you improve your prediction power in general: Imagine that your prediction was wrong. What are some possibilities for why it was wrong?

Oo, that's a good one.

The next step could be hooking up that self-driving mobile home to plumbing infrastructure on the company parking lot. Trailer park company town, here we come.

I share your concerns though, that we will get stuck with an automobile version of the representational train cars of the steam age unless we find ways to channel autonomous driving into mode-independent transportation as a service. Uber as a transitional saviour? Never thought I would write this.

Next requirement: replace/upgrade street parking with theftproof mooring clamps for parcel delivery containers that can then be much smaller than a car (sized as needed), and that could be self-driving or dropped/picked up by a "mothership" truck depending on urgency and/or technology. With that service in place, you could just summon transportation for your shopping bags, alleviating the trunk anxiety often associated with mode-independent transportation as a service.

This analysis is flawed. You can already do all of this internet browsing and whatnot that you can't do on a car on commuting modes where you're a passenger; a bus, or on a subway, or sometimes in a carpool. But that doesn't make people tolerate longer commutes on those modes.

Yes it does - people commute relatively happily up to two hours on a train - distances most people wouldn't consider driving - precisely because they can work effectively while commuting so they aren't losing time.

Sitting comfortably in a car with space and silence is not sufficiently analogous to public transport for the analysis to be flawed on this account.

And how many people on Caltrain or a major subway can actually even get a seat and space for comfortably sing a laptop during commuter hours?

This could be some US thing, but in Europe trains are quiet and comfortable enough that plenty of people work/commute on them.

And anyway it's not like modern offices are quiet, interruption-free workspaces either.

I had no problem commuting by train every day for 70 minutes plus the 20 minute drive to the train station, each way. Because I could get work done on the train.

Self driving minibuses solves mass transits last mile problem just saying. Cause no one is mentioning that.

Self driving cars aren't going to make peoples commutes from Tracey to Moutainview any faster.

I think there's a simple solution:

Zone to Zone travel tax based on time of the day.

This tax wont apply to public transit, or shared rides (like UberPool, Lyft Line, Waze carpool etc). Applies to all other vehicles, even AV if it is a personal/commercial use thats not meant for shared rides, even if HOV (so that fewer people are looking for parking, blocking / flooding the streets in am/pm due to parking).

any thoughts?

We shouldn’t blame autonomous vehicles. Unaffordable housing is causing sprawl.

There need to be better parking solutions for any of that to actually happen.

I think it would be positive. We will sprawl so much that we end up repopulating much of the area what we left previously.

Suburbua (or sleeper districts) around city core is sprawl. Semi-rural settlements all over the map is not sprawl. It is normawl.

Add more telecommuting and basic income, and we're all set.

Suburbs were also originally supposed to be pastoral garden cities. Usually the ideal of planners and technologists falls prey to the reality of mass-market commoditization.

Aren't them? I guess you was never exposed much to other ways of mass urbanization.

Like this: http://www.vsedomarossii.ru/photos/area_77/city_2894/street_...

Or this: https://img.thedailybeast.com/image/upload/v1492112219/artic...

You will have to admit that suburbs are pretty pastoral.

I lived in an apartment building just like the first one in your photo until not that long ago (I now also live in a 8-storey apartment building, but it's a little smaller compared to the first one) and I'd take living in such a building over living in a suburbia-like hell every day of the year (this happens in an big East-European city).

Living in that type of building meant that the tram-station was literally 50 meters outside of my building and a metro station a mere 5-minute walk away, there was a school just bellow my apartment's window (I could here the children playing in the school's yard in the morning) and a kindergarten 100 meters from my building's entrance and the same tram would take me to a Walmart-like store 3 stations away pretty easily (yeah, you don't need a car to do shopping).

And on top of that, having a city that is comprised of mostly tall apartment buildings means that nature is a very short drive away (either with one's car or with public transport), but nowadays, as the suburbia phenomenon has also invaded the city of which I'm talking about, it means that in order to "reach" nature one has to drive further and further away.

You describe advantages of transportation and location around the building, not advantages of the building itself. Because crammed building like this usually also means smaller living space, problem with sound from/to neighbors and the street, if you live on a high floor - you need to go up and down (and hope that there's no problem with elevator). You say that nature is too far, but if you have nice garden you can have nature one step away (also, there should be more parks, regardless of if it's suburbia or a city, but it's cheaper to have a park in suburbia). I think best solution is combination of individual homes and apartment buildings (just not giant ones), so we could increase population density and there could be some shops and cafes in walk/bike ride distance. You don't need to always go to walmart to get a load of bread, for that you can occasionally ride there. And self driving cars will only help here.

> you need to go up and down (and hope that there's no problem with elevator).

For the last 7 years I've been only living on the 7th and 8th floor, I think only twice I had problems with the elevator.

> also means smaller living space

I'm very fine with that, I don't need huge spaces to live all of by myself (or with my wife + kids). As a matter of fact I have several coffee shops on a 10-minute walk radius, there's where I also spend most of my free time.

> You say that nature is too far, but if you have nice garden you can have nature one step away (also, there should be more parks, regardless of if it's suburbia or a city, but it's cheaper to have a park in suburbia).

I don't have that much spare time, and as such I don't have time for gardening (plus, I don't like it). On top of that, "raw" nature beats "gardened" nature by several orders of magnitude. I want my kids to be able to wander by themselves in wild-ish forests just outside the city (as I used to do as a kid, while I was living in an communist apartment building), I don't want them to enjoy the sort of "manicured" nature that the suburbia promotes.

> For the last 7 years I've been only living on the 7th and 8th floor, I think only twice I had problems with the elevator.

Still it's a bother, especially if you're a senior citizen. Also you still spend much time just waiting for an elevator and riding it,

> I'm very fine with that, I don't need huge spaces to live all of by myself (or with my wife + kids). As a matter of fact I have several coffee shops on a 10-minute walk radius, there's where I also spend most of my free time.

That's ok, but many people would like something more than a 50 m^2 flat and don't spend most of free time in coffee shops.

> I don't have that much spare time, and as such I don't have time for gardening (plus, I don't like it). On top of that, "raw" nature beats "gardened" nature by several orders of magnitude

I don't mean some fancy garden, just grass and maybe some trees/bushes. And I don't agree that raw nature beats it by several orders of magnitude, of course someone likes it better, and it's no mountains, but it's still real trees, real flower and real grass.

> I want my kids to be able to wander by themselves in wild-ish forests just outside the city (as I used to do as a kid, while I was living in an communist apartment building), I don't want them to enjoy the sort of "manicured" nature that the suburbia promotes.

If you want that than living in a large city is really not an answer. Your kids only can do that if you live on the very edge of the city. And suburbia has more places like that because it has more edges (there's many detached patched of sprawl). Or you can live in a very small city.

You ignore that those advantages require the density of housing provided by the kind of building described by paganel. You can't have low-density housing surrounded by lots of cafés and supermarkets, the economics just don't work out.

You don't need that giant dense buildings for that and you don't need "lots" of cafes etc. 3-4 in a walking distance is better than nothing like in average suburbs. There's thousands people living in 20 minute walk radius and if you add bike ride here, it's even more. Put cluster of reasonably large apartment buildings as a core, cafes and shops in this area and individual homes sprawl around it. I'm sure we can find at what scale economics does work.

Any apartment built in the last 10~15 years should not have those problems. Here is a rendering of an apartment in Gangnam, Seoul, one of the densest cities in the world (about 2x of New York). http://ojsfile.ohmynews.com/STD_IMG_FILE/2016/0330/IE0019412... As you can see, the apartments have parks and playgrounds surrounding it. The short building in the corner is a commercial building, usually with restaurants, cafes, markets, education classrooms, all within short walking distance. Number of elevators typically scale with the building height, the ones in the picture probably have 2~3 elevators, making the possibility that all are out of service unlikely. There's no real problem with street noise (I've lived on the 3rd floor) and with neighbors in typical circumstances (barring things like construction or moving day). Popular starter apartments are around 80m^2 2 bedroom apartments, moving up to 115m^2 3 bedrooms as families get bigger and more established. This might be a problem for you if you like large places to live while living in a city, but that is an anomaly in recent times, I believe, based on what I've seen of older buildings in New York and LA. These kinds of apartments are common even in the suburbs, where there is much less space constraint to need this kind of density, but the density makes everything much more convenient, attracting and being able to sustain more local businesses, which is why even in the suburbs you can have access to half a dozen coffee shops within walking distance.

Why are you comparing to a derelict housing block in Russia and cramped living in Kowloon? There is plenty of high-density housing in western cities as well, and it looks nothing like the pictures. How's this, for example: https://www.google.de/maps/@48.1220008,11.5526623,358a,35y,4... It has:

- much higher density than any suburb - a subway stop and multiple bus stops - a bunch of restaurants and bars - a supermarket and another one just on the other side of the train tracks - multiple childcares - schools in close vicinity

And it's accessible to pedestrians and cyclists.

Suburbs are pastoral in the same way that a Domino's is reflective of a Neapolitan pizza. They certainly have somewhat artificial greenery. But very few suburbs are actually pastoral.

It's interesting to note that Hong Kong, while very urban, is also 40% park. https://www.hongkongfp.com/wp-content/uploads/2016/11/106761...

IMO it's a lot better to have a small amount of highly developed area and lots of pristine, verdant land rather than some cookie-cutter landscaping into the horizon.

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