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He criticizes people arguing for smaller cars closer together as being a linear solution to an exponential problem, but mass transit is also a linear solution t

He criticizes people arguing for smaller cars closer together as being a linear solution to an exponential problem, but mass transit is also a linear solution to the same problem. Build better mass transit, and houses near the stations become more attractive and people move there, which increases usage, and so on. And looking at it from the other end, ever smaller cars jammed ever closer together at the limit tends to the same density as mass transit. (We're nowhere near that now, but I can see us getting much, much closer in an automated driving future.) The key differences end up being routing flexibility, packet size and latency. Mass transit is worse in all three (less flexible and more waiting time are given with mass transit; I'm taking packet size to be a measurement forced space sharing, so big is bad). Its only real advantage is being at the limit for density, a density cars will likely never be able to match. But because it's still linear, it's only a constant factor improvement. (Personally, I travel around London by motorcycle and scooter because public transport is ludicrously inefficient; it multiplies journey time by 2x to 5x. Ironically, it works best if you're elite, i.e. live inside the circle line; but then you might as well cycle.)

arethuza 9y ago
It takes me 35 minutes to take the train from Fife to central Edinburgh - absolutely no chance of doing it by car in that time in the morning. If I had to drive into the center of Edinburgh in the morning I'd probably give it well over an hour and that would ignore the hassle and costs of parking once I get here. Edit: And with the train I can sit and sip coffee and try and spot seals and herons and enjoy the splendid views....
- barrkel 9y ago
  Fife isn't city living; that's not relevant to the article. Mind you, with your self-driving vehicle, you'll be able to sip coffee and spot herons. And I believe packetized self-driving vehicles grouping together into convoys ought to be able to exceed 200mph in the future. That future isn't today, but the article is explicitly forward looking, about geometry that doesn't change. I think the article is ideologically blind to how mass transit has similar supply and demand problems (e.g. when I take the train home, I often have to skip multiple departures due to overcrowding), and it drastically underestimates the potential for technology change.
  - StudentStuff 9y ago
    Stopping distances aren't about to magically improve in the next decade such that any vehicle can speed down the street at 200mph (or anywhere close to that) safely. This whole scheme your dreaming up is just not realistic, the faster you go, the more dangerous a road is for everything else on it, from pedestrians and bikers to other cars sharing the road with you. Making your car drive itself won't magically double road capacity either, as you'd need much more traction & better brakes to support tighter packing of cars in any vaguely safe manner.
    - barrkel 9y ago
      > Stopping distances aren't about to magically improve in the next decade such that any vehicle can speed down the street at 200mph (or anywhere close to that) safely. What makes you think the vehicles wouldn't be coupled together mechanically? Pedestrians wouldn't be on a road going 200mph; I'd expect that kind of road would be fenced off like rail is today, or in a tunnel, and perhaps even be on tracks. The point is that automation will change the nature of transport in ways that don't fit into the current mass transit / individual vehicle binary that we have today. That binary is based on limitations on current technology.
- dboreham 9y ago
  My commute to school and university. Good to know that Heron is still there!
TheCoelacanth 9y ago
It's only a constant factor improvement, but it is a massive constant factor improvement. Mass transit easily scales up to the limits of our building construction abilities. You can only make buildings so tall before you start getting diminishing returns on density because you need to have more and more space taken up with elevators, HVAC, plumbing, etc. Even in an incredibly dense city like Paris, they aren't running out of space to put subway lines. They are limited by by the number of people who need to get places and by the cost of building more subway lines.
- barrkel 9y ago
  Why do you think there are so many scooters and motorcycles in Paris then?
  - TheCoelacanth 9y ago
    Not sure what your point is... Paris doesn't have enough subway lines to handle all transportation needs for everyone, but that's not because they ran out of space to put the subway lines in. It's likely because they have covered enough people's transportation needs that it wouldn't be cost effective to put in more lines.

arethuza 9y ago

It takes me 35 minutes to take the train from Fife to central Edinburgh - absolutely no chance of doing it by car in that time in the morning. If I had to drive into the center of Edinburgh in the morning I'd probably give it well over an hour and that would ignore the hassle and costs of parking once I get here. Edit: And with the train I can sit and sip coffee and try and spot seals and herons and enjoy the splendid views....

barrkel 9y ago
Fife isn't city living; that's not relevant to the article. Mind you, with your self-driving vehicle, you'll be able to sip coffee and spot herons. And I believe packetized self-driving vehicles grouping together into convoys ought to be able to exceed 200mph in the future. That future isn't today, but the article is explicitly forward looking, about geometry that doesn't change. I think the article is ideologically blind to how mass transit has similar supply and demand problems (e.g. when I take the train home, I often have to skip multiple departures due to overcrowding), and it drastically underestimates the potential for technology change.
- StudentStuff 9y ago
  Stopping distances aren't about to magically improve in the next decade such that any vehicle can speed down the street at 200mph (or anywhere close to that) safely. This whole scheme your dreaming up is just not realistic, the faster you go, the more dangerous a road is for everything else on it, from pedestrians and bikers to other cars sharing the road with you. Making your car drive itself won't magically double road capacity either, as you'd need much more traction & better brakes to support tighter packing of cars in any vaguely safe manner.
  - barrkel 9y ago
    > Stopping distances aren't about to magically improve in the next decade such that any vehicle can speed down the street at 200mph (or anywhere close to that) safely. What makes you think the vehicles wouldn't be coupled together mechanically? Pedestrians wouldn't be on a road going 200mph; I'd expect that kind of road would be fenced off like rail is today, or in a tunnel, and perhaps even be on tracks. The point is that automation will change the nature of transport in ways that don't fit into the current mass transit / individual vehicle binary that we have today. That binary is based on limitations on current technology.
dboreham 9y ago
My commute to school and university. Good to know that Heron is still there!

TheCoelacanth 9y ago

It's only a constant factor improvement, but it is a massive constant factor improvement. Mass transit easily scales up to the limits of our building construction abilities. You can only make buildings so tall before you start getting diminishing returns on density because you need to have more and more space taken up with elevators, HVAC, plumbing, etc. Even in an incredibly dense city like Paris, they aren't running out of space to put subway lines. They are limited by by the number of people who need to get places and by the cost of building more subway lines.

barrkel 9y ago
Why do you think there are so many scooters and motorcycles in Paris then?
- TheCoelacanth 9y ago
  Not sure what your point is... Paris doesn't have enough subway lines to handle all transportation needs for everyone, but that's not because they ran out of space to put the subway lines in. It's likely because they have covered enough people's transportation needs that it wouldn't be cost effective to put in more lines.