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Why driverless cars may mean jams tomorrow

economist.com

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Re: Why driverless cars may mean jams tomorrow

#41

Post by ams6110 »

softgrow wrote: post #15

Driverless cars will bring safer roads in terms of exposure measures like deaths/injuries per 1 Million/km. They will also lower the monetary cost of transporting a person per km due to reduction in fleet size and optimised driving and resource allocation. This will benefit nations and economies in providing more economic growth, employment etc by moving more people and goods over the same road network and a smaller…

That's not exactly what "free" means in an economic context, but probably doesn't alter your point.

Something is "free" if, at a price of zero, there is enough supply to meet demand.

Re: Why driverless cars may mean jams tomorrow

#42

Post by Broken_Hippo »

jejones3141 wrote: post #38
skgoa wrote: post #17

Earlier quoted context omitted.

You mean sharing a ride like say a big, long vehicle with lots of seats that visits a number of stops on a route? Yeah, that would be a great idea. We could improve this even further by giving the ride-share vehicle it's own lane, then turn both the wheels and the road surface into metal to reduce friction. BRB, going to the patent office... Not to be too snarky, but as a non-american it has been amazing to watch the…

It's not a good thing for the rider. You can only ride where and when the state decides you can ride, and have to organize your life around it. Your residence or your destination is likely some distance from a stop, so you have the problem of getting to or from it, possibly in bad weather. You're herded like cattle into cramped, uncomfortable seats, with minimal provision for anything you may be carrying. What's good…

"What's good about that?"

You get exercise. Most people slack off in bad weather, so there is a bonus (I'm also in Norway. I walk and ride the bus 95% of the time. You get used to it and dress appropriately.) Sure, most public transport doesn't provide door to door service - cabs do, though, and those generally have more options. And though there are limitations, you don't have to own a car nor pay for all the expenses with it.

Some of these are bad or incomplete public transport issues, which means they can be improved.

Re: Why driverless cars may mean jams tomorrow

#43

Post by majewsky »

CPLX wrote: post #37
nkoren wrote: post #30

Earlier quoted context omitted.

No, not like that. Trains work well for arterial routes that need to carry large volumes of people along predictable corridors at predictable times of day -- eg., for commuting. And yes America certainly needs to get better at investing in them. But trains don't work at all well for serving smaller volumes of people moving in stochastic patterns at arbitrary times of day. Neither do buses. Cars serve this need very w…

> But trains don't work at all well for serving smaller volumes of people moving in stochastic patterns at arbitrary times of day. Neither do buses. Have you ever been to Switzerland?

Or to Europe, for that matter.

> incidental travel [is] actually the majority of trips that people take: going shopping, visiting friends, going to the doctor's, eating out, etc. [...] People own cars to serve this need, because nothing else will

I use public transit (or just plain walking) for all of these tasks. Admittedly, this only works because I live in a city rather than a village in the countryside: When I visit my brother who lives in a small village, I arrange that he picks me up with his car from the nearest train station.

But it's nothing like grandparent's very American perspective of "public transit is only good for commuting".

Re: Why driverless cars may mean jams tomorrow

#44

Post by majewsky »

skgoa wrote: post #35
nkoren wrote: post #30

Earlier quoted context omitted.

No, not like that. Trains work well for arterial routes that need to carry large volumes of people along predictable corridors at predictable times of day -- eg., for commuting. And yes America certainly needs to get better at investing in them. But trains don't work at all well for serving smaller volumes of people moving in stochastic patterns at arbitrary times of day. Neither do buses. Cars serve this need very w…

I don't disagree. In fact I work on software for cars, so my career depends on personal transport staying relevant. However, that doesn't adress the question of whether automated cars will increase or decrease traffic. The original claim was that automated cars will reduce traffic by being more efficient (somehow) and people sharing them for trips. I pointed out that we have the sharing aspect of the issue largely fi…

> Because the benefits people claim stem from automation actually stem from public transport.

What about more efficient use of roads because automated cars have a shorter reaction time and thus do not need as much safety distance between them?

Re: Why driverless cars may mean jams tomorrow

#45

Post by dmichulke »

ams6110 wrote: post #41
softgrow wrote: post #15

Driverless cars will bring safer roads in terms of exposure measures like deaths/injuries per 1 Million/km. They will also lower the monetary cost of transporting a person per km due to reduction in fleet size and optimised driving and resource allocation. This will benefit nations and economies in providing more economic growth, employment etc by moving more people and goods over the same road network and a smaller…

That's not exactly what "free" means in an economic context, but probably doesn't alter your point. Something is "free" if, at a price of zero, there is enough supply to meet demand.

Interesting definition.

It follows that nothing is universally free, it can only be free within spatial (and probably temporal) constraints. The usual candidates (water, air) are certainly not free everywhere.

Re: Why driverless cars may mean jams tomorrow

#46

Post by ams6110 »

alanfranzoni wrote: post #24
skgoa wrote: post #17

Earlier quoted context omitted.

You mean sharing a ride like say a big, long vehicle with lots of seats that visits a number of stops on a route? Yeah, that would be a great idea. We could improve this even further by giving the ride-share vehicle it's own lane, then turn both the wheels and the road surface into metal to reduce friction. BRB, going to the patent office... Not to be too snarky, but as a non-american it has been amazing to watch the…

I'm not american, and I use public transport in Italy. But the public transport is simply ineffective a) from a door-to-door timing perspective and b) from a flexibility perspective. Sure, I don't live in a big city, so maybe the public transport is not as effective as it could be; but many people I spoke with even in London (and other places like Berlin, Paris, Milan) seem to share the same suffering: constantly usi…

Where I live, the buses cause significant traffic problems. They stop in driving lanes to pick up and disgorge passengers. Their stops are out of sync with traffic signals. They are slow.

Self-driving cars available on demand might solve a lot of that. However, like most "utopias," I don't think we will ever achive the ideal efficiencies that self-driving car advocates imagine. The real world is too complicated.

Re: Why driverless cars may mean jams tomorrow

#47

Post by nkoren »

majewsky wrote: post #43
CPLX wrote: post #37

Earlier quoted context omitted.

> But trains don't work at all well for serving smaller volumes of people moving in stochastic patterns at arbitrary times of day. Neither do buses. Have you ever been to Switzerland?

Or to Europe, for that matter. > incidental travel [is] actually the majority of trips that people take: going shopping, visiting friends, going to the doctor's, eating out, etc. [...] People own cars to serve this need, because nothing else will I use public transit (or just plain walking) for all of these tasks. Admittedly, this only works because I live in a city rather than a village in the countryside: When I vi…

> Or to Europe, for that matter.

Er, yeah. I reside in the UK, and have lived and worked extensively in Europe. As a public transport planner. So I kinda know what I'm talking about here.

I use public transport for all of those tasks too -- because I live in zone 2 of London. If I lived in a much smaller city, or even in zone 5, it would be much more difficult for me to do so. The ability of public transport to serve incidental travel depends greatly on the size and shape of the city, and on your place within it. So yes, it can work for some people -- but certainly not for all people, nor even for most people. Not even in Switzerland.

America is egregious for how badly its cities are laid out; with the exception of New York, they are almost wholly ill-served by public transport. Fun fact: with an average 9% occupancy, buses in America produce more emissions per passenger-mile than single-occupancy SUVs. This is not a problem that cannot be solved with more mass transport: it requires entirely new forms of transport, or spatial reorganisation of the city, or (most likely) both.

Re: Why driverless cars may mean jams tomorrow

#48

Post by chopin »

alanfranzoni wrote: post #20
chillydawg wrote: post #12

Earlier quoted context omitted.

Nobody really likes ride sharing, though. That's why people drive in the first place.

Do people really dislike ride sharing more than public transport? Why? I dislike public transport when it's ineffective. It takes me about 45 minutes to get to work by walking + train, and there's about one train every hour (less often in the morning), so it's inflexible. If I go by bike, it's about 55 minutes (but then I need a shower, which can take a bit more if your company doesn't provide the right facilities).…

If you rideshare it's likely to take longer than 25 minutes to get to work unless all sharing people happen to work and live at the same point.

Re: Why driverless cars may mean jams tomorrow

#49

Post by nkoren »

skgoa wrote: post #35
nkoren wrote: post #30

Earlier quoted context omitted.

No, not like that. Trains work well for arterial routes that need to carry large volumes of people along predictable corridors at predictable times of day -- eg., for commuting. And yes America certainly needs to get better at investing in them. But trains don't work at all well for serving smaller volumes of people moving in stochastic patterns at arbitrary times of day. Neither do buses. Cars serve this need very w…

I don't disagree. In fact I work on software for cars, so my career depends on personal transport staying relevant. However, that doesn't adress the question of whether automated cars will increase or decrease traffic. The original claim was that automated cars will reduce traffic by being more efficient (somehow) and people sharing them for trips. I pointed out that we have the sharing aspect of the issue largely fi…

Okay, so we definitely agree that automation-driven traffic-less utopia is a red herring! Certainly if personal vehicles are replaced 1:1 by automated personal vehicles, congestion will, on average, get worse. Even if they're replaced by automated taxis -- eliminating the need for parking -- this will lead to at least a ~30% increase in vehicles actively on the road due to empty vehicle movements. And that's before you factor in induced demand, which would be significant.

Where I think we disagree is here:

> we have the sharing aspect of the issue largely figured out already.

No, we really haven't. With non-automated vehicles, sharing only works in situations where you can amortise the cost of a driver. This requires maintaining an average occupancy of > 25 people, which in turn limits you to fixed routes at fixed schedules. Hence, bad for serving incidental demand. Automated vehicles open up the possibility of having a range of smaller vehicles that are demand-responsive yet shared. This would bridge the gap between current private and public transport options, serving a substantial travel regime where current technologies are inefficient.

Re: Why driverless cars may mean jams tomorrow

#50

Post by carlmr »

gryzilepek wrote: post #26
carlmr wrote: post #7

Earlier quoted context omitted.

I also don't follow that argument. IMHO accidents and bad swarm behavior (people following too closely, switching lanes too often, accelerating and braking too much) lead to traffic jams. If we can get that improved our roads could take twice the cars.

You don't get the point: if you create an empty space on the roads (whatever solution you invent), people will start occupying it immediately, and you face the same problem again.

No reason to get offensive, I do get the point, I'm just saying the point makes no sense. If we get to a fully automated future (that is without human drivers interfering), we can get to twice the occupancy which is I think more than the amount of children and seniors now driving cars that didn't before, and still have less traffic.

It just runs counter to reality to think that every empty space you create is occupied immediately. After all there are less congested cities and more congested cities. Mostly because the less congested cities have a higher road/road width/road quality to commuter ratio. That's why Seattle and SF have huge issues. With the water and mountains it's impossible to get a good infrastructure to population ratio. And no, cities with better traffic don't start going on the road to occupy space just because it's there. There's always a need for people to commute paired with inadequate infrastructure.

By utilising the infrastructure better, self-driving cars can basically increase one side of the fraction. Higher number of drivers will probably happen (seniors and children especially who couldn't drive before), but they also usually I doubt it's even more than 20-30%, seniors won't start commuting to jobs they don't have, children have more vacation, they're already only a smaller part of the population.

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