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> If you are going to geofence self-driving cars it's questionable whether they are better than trains and buses They run on demand 24/7, they run point to poi

> If you are going to geofence self-driving cars it's questionable whether they are better than trains and buses They run on demand 24/7, they run point to point, you never have to stand, you don't have to share the space with people who behave antisocially, you have a range of choice of comfort options, there are unlimited competitors for the same route driving prices down and service standards up. So, quite a few game changers for me at least. If you live/work outside the geofence, this obviously doesn't apply, but if you do then you get the advantages 80% of the time, and for day to day purposes it absolutely is fundamentally better than trains and buses.

Al-Khwarizmi 8y ago
And they pollute much more and take more space.
- davnicwil 8y ago
  I'm first in line to agree with you, I think cars in cities are awful because of these two problems, and honestly I support all sensible efforts to reduce the number of (current generation) cars on city streets. I'm also a daily user of public transport in a major world city, however, and whilst buses and trains work they also have the fundamental problems highlighted above that are in my view insurmountable, and which (self driving) cars solve. So I'm in a dilemma over whether I think they'd be an improvement, but I ultimately believe they would be. But yes, absolutely pollution and space saving would have to be addressed. I'm optimistic they could be: Pollution: hopefully solvable with electric. Yes, of course, there are efficiency gains that trains/buses would perhaps always have (having to move many small things rather than one big thing carrying the same number of people) but I can see electric reducing the absolute level of pollution from cars to a point where it basically doesn't matter. Maybe overly optimistic, but I hope that'll happen. Space: Driverless cars, particularly electric driverless cars, can be much smaller and can drive much closer together. Different cities have different challenges, but I don't see why we couldn't get to a situation where roads might effectively have capacity for 2x vehicles across and 2-3x vehicles along if the vehicles can be coordinated to drive closer together and are physically smaller (remember that on-demand unlocks certain design constraints - you don't have to provision for peak - if the average number of passengers is 1.5, then most cars on the road could be ultra small 2 seaters). Again lots of conjecture and optimism here, and I am probably assuming that 'manual' cars would eventually disappear or be banned at least from cities too, but nonetheless I think there is hope here.
  - jacques_chester 8y ago
    Public transport will always be able to pack more people into the same space. There is a minimum amount of space occupied by the vehicle's own matter. The ratio of that material to the occupant is a scaling law: the larger the vehicle, the higher the volume-to-surface, the denser the passenger-to-vehicle ratio can be. A standard R160 subway car carries up to about 250 people in an area that would be about the same as 5 Corollas positioned nose to tail, a starting ratio of about 10:1. If cars are made twice as dense, it's still 5:1. This is ordinary batching. The only thing that can carry more people more densely than a bus or train is the footpath.
    - davnicwil 8y ago
      Yes you're absolutely correct - I guess my main question is could the space savings, like the pollution savings, be 'good enough' for it not to matter in practice, assuming that driverless cars become the 80% usecase for road traffic and today's 'massive 5 seater car for an average of 2 people' model goes away. It's also important to point out that of course, buses and trains shouldn't go away - they could indeed also have a bunch of problems solved by being self driving too, most notably the 24/7 running thing - they'd just be another option in the mix.
    - rhacker 8y ago
      > Public transport will always be able to pack more people into the same space. While that's true, that's also just an argument for something we already understand. Are there possible arguments to be made about the number of busses and routes because it's not taking people point to point. What about the lul-time of day, where on-demand model is more efficient than driving empty busses around. They reduce schedules obviously. But now you're punishing passengers that start a shift at noon. There are more things to solve than just "the least amount of pollution and space." Totally unrelated but similar argument. The FAA introduced a new system and process for creating standard flight paths a few years ago. Flights around the nation started doing new things. TONS of people are now inundated by jet noise. They're now discussing just going back in certain areas to the old routes. They ONLY optimized for efficiency of route and didn't consider anything else.
- dfrage 8y ago
  Prior to low cost ride sharing, a good bus system that people will use as an alternative to cars pollutes more because it has to run a lot mostly empty buses to satisfy long tail demand. To the extend low cost ride sharing is a short term unicorn phenomena, that will again become true, although self-contained electric buses might change that a bit. Maybe someday self-driving cars will change this, but that's not in the predictable, foreseeable future.
  - davnicwil 8y ago
    Yeah this is the really interesting part - like where does the 'supply provisioned precisely to match demand' thing for self driving cars meet the 'buses/trains are more efficient assuming some % capacity filled', how does that relate to demand changing with hours of the day, where people live, etc. It's just a fascinating optimisation problem. I think the answer is far from clear, and certainly couldn't be reliably approximated without lots of real world data.
- crazygringo 8y ago
  Not necessarily, it's not that simple. I've been on double-length public buses where I was the only passenger for most of the journey. And many times where there were only 1 or 2 other people. This is necessary e.g. at night where a bus only runs every 30 minutes, there has to be a bus, but there just aren't that many people. Obviously in this case individual cars would pollute much less, and even take up less space. Any realistic solution for a city is going to combine self-driving cars for the long tail of origins/destinations and times, with public transit for the busiest routes at the busiest times, including links between the two. I'd love to be able to take a self-driving car from a house in Queens directly to the subway, the subway to Brooklyn, and then another self-driving car to my final destination that's 20 blocks away from the subway.
  - prolepunk 8y ago
    On average public transit produces 2% of pollution but transport about 28% of riders. (I don't remember where exactly I got the numbers but I've seen them in a few places). The buses need to run at night so the people can rely on them during the day -- it's just the price of public transit, the public uses transit way more if buses run on 10-minute interval during off-peak rather than 30-minut interval. (another study I can't find right now). I think as programmers we tend to try and optimize problem for least pollution, but the problem here lies in the domains of sociology and urban planning; we might not be the most qualified people to solve it. For example if buses pollute 3% because of the extra buses on off-peak routes but now more people use them, this would have net effect of reducing pollution.
    - SilasX 8y ago
      Was going to downvote but this probably merits a reply. All your points are correct, but you're not responding to the point that SDCs can be superior to buses for those low-capacity times. If it were one or the other, then yes, buses could be less pollution on average, but that doesn't address the case the parent was talking about.
esotericn 8y ago
Yeah, this is something that really bugs me about public transport. It's simply not acceptable to have to stand on a bus. Ever. It should be treated as some sort of breakdown/failure condition. If it happens on more than a few % of journeys, the public transport authority should be putting on more buses. Otherwise people are just going to take their car because they actually have control over their own comfort. With trains it's a little harder due to physical constraints on the network, but with buses it's inexcusable to not just have more capacity, particularly at peak time (London buses get silly in the morning peak, for example). edit: Replies here are completely missing the point. A car has comfortable seats whenever you want them. It's honestly a comical joke to have to explain "why I don't want to stand up". The obvious answer is because I don't have to in my car. Public transport can be, and should be as comfortable as that. It can't be as private, sure, but there's no need for it to feel like cattle class. I'd gladly pay twice as much for it to be better. It easily could be; in London for example if everyone gave up their cars and put the money towards public transport we could double or triple the number of buses.
- bcraven 8y ago
  Why is it not acceptable to stand on a bus? It increases capacity hugely and if you're only going a few stops it makes perfect sense. Most buses are rated for "X Standing, Y Seated" passengers.
  - bonesss 8y ago
    Also, wishing for a blanket increase in total number of busses by some huge percentage to avoid anyone standing probably sounds like a real nice plan until you have to pay for it... Capacity management isn't as easy as throwing drivers and busses at the problem.
  - esotericn 8y ago
    Because people will take a taxi or self driving car instead. You're making a comparison here that's based on having no other choice. There is obviously a difference between a 5 min journey down the road and a 30+ minute commute.
SiVal 8y ago
I totally agree, and they can take care of the last mile problem for trains at both ends, making trains more practical. And GP said, "If the solution is flawed even a little bit, people will die." Well, yes, and if humans drive, people will die. If the flawed machines reach the point where they are provably statistically better than the flawed people who currently drive, lawsuits claiming that people who choose to drive and get in accidents are negligent will cause insurance companies to jack up the rates on "self-drivers". That's where the state-change sigmoid curve will suddenly turn upward.
blablablerg 8y ago
Also if you live for a part inside the geofence, You can give full AI autonomy inside the geofence and take over outside. This would be especially useful when you have to travel long distances on the highway.
gnopgnip 8y ago
The cost floor of driving even with automation is above the cost of public transportation in most cases. Because of traffic, the service standard will never approach public transportation in dense areas

Al-Khwarizmi 8y ago

And they pollute much more and take more space.

davnicwil 8y ago
I'm first in line to agree with you, I think cars in cities are awful because of these two problems, and honestly I support all sensible efforts to reduce the number of (current generation) cars on city streets. I'm also a daily user of public transport in a major world city, however, and whilst buses and trains work they also have the fundamental problems highlighted above that are in my view insurmountable, and which (self driving) cars solve. So I'm in a dilemma over whether I think they'd be an improvement, but I ultimately believe they would be. But yes, absolutely pollution and space saving would have to be addressed. I'm optimistic they could be: Pollution: hopefully solvable with electric. Yes, of course, there are efficiency gains that trains/buses would perhaps always have (having to move many small things rather than one big thing carrying the same number of people) but I can see electric reducing the absolute level of pollution from cars to a point where it basically doesn't matter. Maybe overly optimistic, but I hope that'll happen. Space: Driverless cars, particularly electric driverless cars, can be much smaller and can drive much closer together. Different cities have different challenges, but I don't see why we couldn't get to a situation where roads might effectively have capacity for 2x vehicles across and 2-3x vehicles along if the vehicles can be coordinated to drive closer together and are physically smaller (remember that on-demand unlocks certain design constraints - you don't have to provision for peak - if the average number of passengers is 1.5, then most cars on the road could be ultra small 2 seaters). Again lots of conjecture and optimism here, and I am probably assuming that 'manual' cars would eventually disappear or be banned at least from cities too, but nonetheless I think there is hope here.
- jacques_chester 8y ago
  Public transport will always be able to pack more people into the same space. There is a minimum amount of space occupied by the vehicle's own matter. The ratio of that material to the occupant is a scaling law: the larger the vehicle, the higher the volume-to-surface, the denser the passenger-to-vehicle ratio can be. A standard R160 subway car carries up to about 250 people in an area that would be about the same as 5 Corollas positioned nose to tail, a starting ratio of about 10:1. If cars are made twice as dense, it's still 5:1. This is ordinary batching. The only thing that can carry more people more densely than a bus or train is the footpath.
  - davnicwil 8y ago
    Yes you're absolutely correct - I guess my main question is could the space savings, like the pollution savings, be 'good enough' for it not to matter in practice, assuming that driverless cars become the 80% usecase for road traffic and today's 'massive 5 seater car for an average of 2 people' model goes away. It's also important to point out that of course, buses and trains shouldn't go away - they could indeed also have a bunch of problems solved by being self driving too, most notably the 24/7 running thing - they'd just be another option in the mix.
  - rhacker 8y ago
    > Public transport will always be able to pack more people into the same space. While that's true, that's also just an argument for something we already understand. Are there possible arguments to be made about the number of busses and routes because it's not taking people point to point. What about the lul-time of day, where on-demand model is more efficient than driving empty busses around. They reduce schedules obviously. But now you're punishing passengers that start a shift at noon. There are more things to solve than just "the least amount of pollution and space." Totally unrelated but similar argument. The FAA introduced a new system and process for creating standard flight paths a few years ago. Flights around the nation started doing new things. TONS of people are now inundated by jet noise. They're now discussing just going back in certain areas to the old routes. They ONLY optimized for efficiency of route and didn't consider anything else.
dfrage 8y ago
Prior to low cost ride sharing, a good bus system that people will use as an alternative to cars pollutes more because it has to run a lot mostly empty buses to satisfy long tail demand. To the extend low cost ride sharing is a short term unicorn phenomena, that will again become true, although self-contained electric buses might change that a bit. Maybe someday self-driving cars will change this, but that's not in the predictable, foreseeable future.
- davnicwil 8y ago
  Yeah this is the really interesting part - like where does the 'supply provisioned precisely to match demand' thing for self driving cars meet the 'buses/trains are more efficient assuming some % capacity filled', how does that relate to demand changing with hours of the day, where people live, etc. It's just a fascinating optimisation problem. I think the answer is far from clear, and certainly couldn't be reliably approximated without lots of real world data.
crazygringo 8y ago
Not necessarily, it's not that simple. I've been on double-length public buses where I was the only passenger for most of the journey. And many times where there were only 1 or 2 other people. This is necessary e.g. at night where a bus only runs every 30 minutes, there has to be a bus, but there just aren't that many people. Obviously in this case individual cars would pollute much less, and even take up less space. Any realistic solution for a city is going to combine self-driving cars for the long tail of origins/destinations and times, with public transit for the busiest routes at the busiest times, including links between the two. I'd love to be able to take a self-driving car from a house in Queens directly to the subway, the subway to Brooklyn, and then another self-driving car to my final destination that's 20 blocks away from the subway.
- prolepunk 8y ago
  On average public transit produces 2% of pollution but transport about 28% of riders. (I don't remember where exactly I got the numbers but I've seen them in a few places). The buses need to run at night so the people can rely on them during the day -- it's just the price of public transit, the public uses transit way more if buses run on 10-minute interval during off-peak rather than 30-minut interval. (another study I can't find right now). I think as programmers we tend to try and optimize problem for least pollution, but the problem here lies in the domains of sociology and urban planning; we might not be the most qualified people to solve it. For example if buses pollute 3% because of the extra buses on off-peak routes but now more people use them, this would have net effect of reducing pollution.
  - SilasX 8y ago
    Was going to downvote but this probably merits a reply. All your points are correct, but you're not responding to the point that SDCs can be superior to buses for those low-capacity times. If it were one or the other, then yes, buses could be less pollution on average, but that doesn't address the case the parent was talking about.

esotericn 8y ago

Yeah, this is something that really bugs me about public transport. It's simply not acceptable to have to stand on a bus. Ever. It should be treated as some sort of breakdown/failure condition. If it happens on more than a few % of journeys, the public transport authority should be putting on more buses. Otherwise people are just going to take their car because they actually have control over their own comfort. With trains it's a little harder due to physical constraints on the network, but with buses it's inexcusable to not just have more capacity, particularly at peak time (London buses get silly in the morning peak, for example). edit: Replies here are completely missing the point. A car has comfortable seats whenever you want them. It's honestly a comical joke to have to explain "why I don't want to stand up". The obvious answer is because I don't have to in my car. Public transport can be, and should be as comfortable as that. It can't be as private, sure, but there's no need for it to feel like cattle class. I'd gladly pay twice as much for it to be better. It easily could be; in London for example if everyone gave up their cars and put the money towards public transport we could double or triple the number of buses.

bcraven 8y ago
Why is it not acceptable to stand on a bus? It increases capacity hugely and if you're only going a few stops it makes perfect sense. Most buses are rated for "X Standing, Y Seated" passengers.
- bonesss 8y ago
  Also, wishing for a blanket increase in total number of busses by some huge percentage to avoid anyone standing probably sounds like a real nice plan until you have to pay for it... Capacity management isn't as easy as throwing drivers and busses at the problem.
- esotericn 8y ago
  Because people will take a taxi or self driving car instead. You're making a comparison here that's based on having no other choice. There is obviously a difference between a 5 min journey down the road and a 30+ minute commute.

SiVal 8y ago

I totally agree, and they can take care of the last mile problem for trains at both ends, making trains more practical. And GP said, "If the solution is flawed even a little bit, people will die." Well, yes, and if humans drive, people will die. If the flawed machines reach the point where they are provably statistically better than the flawed people who currently drive, lawsuits claiming that people who choose to drive and get in accidents are negligent will cause insurance companies to jack up the rates on "self-drivers". That's where the state-change sigmoid curve will suddenly turn upward.

blablablerg 8y ago

Also if you live for a part inside the geofence, You can give full AI autonomy inside the geofence and take over outside. This would be especially useful when you have to travel long distances on the highway.

gnopgnip 8y ago

The cost floor of driving even with automation is above the cost of public transportation in most cases. Because of traffic, the service standard will never approach public transportation in dense areas