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Even in cities with good public transportation an autonomous vehicle will be faster than public transportation. Especially when you don't have to park. Gridloc

Even in cities with good public transportation an autonomous vehicle will be faster than public transportation. Especially when you don't have to park. Gridlocked Manhattan is an exception. But for most trips in most places a car will be faster. Especially if public transportation requires switching one or more lines.

CamperBob2 10y ago
Be prepared to be downmodded by HN'ers who seem to think that the entire purpose of municipal transit is to move the largest possible number of people per hour from one train station where they don't want to be to another train station where they also don't want to be. Of course autonomous vehicles are going to render fixed-rail systems irrelevant... or at least, they will if they're implemented properly. "Gridlocked Manhattan" is only gridlocked because the vehicles doing the gridlocking aren't talking to a central authority, or to each other. But what seems like common sense to me has proven to be a surprisingly hard sell among technologically-literate people who I'd expect to understand it intuitively. People on HN really, really like trains.
- oasisbob 10y ago
  > Of course autonomous vehicles are going to render fixed-rail systems irrelevant... I'm not sure everyone is willing to take that as a statement of fact. I'm sure not. Can you point to a single transportation expert who believes that centrally orchestrated single-occupancy vehicles are a solution for transportation capacity problems? The difference in lane throughput between single occupancy vehicles and mass transit is staggering. Part of the benefit of rail is that it can use dedicated facilities that are deconflicted. Autonomous vehicles still need to deal with red lights, pedestrians, cyclists, and limits on safe acceleration/deceleration. Here in Seattle our light rail system is hobbled because of non-grade-separated parts of the line - which despite having signal priority is restricted in its operation (station dwell times, # of trains in operation, train separation) because of conflicting cross streets. A central authority is NOT a panacea. With human drivers, lane density tops out at somewhere around ~900 vehicles per hour. Let's say automatic cars can somehow double that - to 1800 vehicles per hour. Even dedicated bus lanes can move 6000 people per hour. Forget Manhattan which is a beast of its own scale - look at Chicago mass transit which moves over a million people a day. You're sure you could replace the capacity of rush-hour Red Line trains at crush capacity with the surface streets? Really? Where would you park these cars? Where would everyone get in and out of the cars? (On/off boarding is the scaling limit for bus lanes - that alone is enough to sink your plan.) You do realize the irony in having faith that centralized coordination between autonomous vehicles will lead to these improvements?
  - CamperBob2 10y ago
    Even dedicated bus lanes can move 6000 people per hour. But not where and when they want. Passengers-per-hour figures are simply measuring the wrong thing. Forget Manhattan which is a beast of its own scale - look at Chicago mass transit which moves over a million people a day. You're sure you could replace the capacity of rush-hour Red Line trains at crush capacity with the surface streets? Really? Where would you park these cars? Considering that there won't need to be as many cars, parking won't be a huge issue. Cars that spend most of the day and all night sitting in parking spaces are a waste of both resources and real estate. In an optimal scenario there wouldn't be a need for any parking spaces at all. Here's a thought experiment for you: take all the taxicabs off the streets of NYC, and replace them with privately-owned cars. Hell of a mess, isn't it? Nowhere to park between Boston and Philly. Now go the other direction, and imagine that every single passenger car that isn't a taxicab simply isn't there at all. It should be obvious that there would be plenty of room in that scenario, both on the streets and in the parking garages. Every single objection you raise is an example of "fighting the last war." You're pitting the worst aspects of the status quo against the best aspects of your favored solution. This happens time and again when these threads come up. Can you point to a single transportation expert who believes that centrally orchestrated single-occupancy vehicles are a solution for transportation capacity problems? No, but I'm less than impressed with the "transportation experts" I've encountered around here (Seattle area as well.) It seems self-evident that planners who devise fixed-rail systems with 25-35 year construction horizons while not even considering the arrival of autonomous vehicles are not competent at their jobs.
    - oasisbob 10y ago
      > It should be obvious that there would be plenty of room in that scenario, both on the streets and in the parking garages. No! It's absolutely not obvious. My biggest problem with your argument is that you're taking it for granted that streets can move as many cars as you think they can. They can't. For the sake of argument, I'm willing to entertain the idea that you can double throughput through automation, and that simply isn't enough for such a low-density form of transportation. Again - picture your system in Chicago where it moves 300,000 people into the downtown loop during the commuting rush-hour. Nobody owns any of these cars, so there isn't any parking to worry about. Fine. Where do these 300,000 people get in and out of their cars? Remember - bus lanes can't even scale past 6,000 people an hour per lane because of the need to get people on and off. Don't forget that these throughput numbers are under best-case scenarios, for smooth flowing traffic. We haven't even discussed intersections...

CamperBob2 10y ago

Be prepared to be downmodded by HN'ers who seem to think that the entire purpose of municipal transit is to move the largest possible number of people per hour from one train station where they don't want to be to another train station where they also don't want to be. Of course autonomous vehicles are going to render fixed-rail systems irrelevant... or at least, they will if they're implemented properly. "Gridlocked Manhattan" is only gridlocked because the vehicles doing the gridlocking aren't talking to a central authority, or to each other. But what seems like common sense to me has proven to be a surprisingly hard sell among technologically-literate people who I'd expect to understand it intuitively. People on HN really, really like trains.

oasisbob 10y ago
> Of course autonomous vehicles are going to render fixed-rail systems irrelevant... I'm not sure everyone is willing to take that as a statement of fact. I'm sure not. Can you point to a single transportation expert who believes that centrally orchestrated single-occupancy vehicles are a solution for transportation capacity problems? The difference in lane throughput between single occupancy vehicles and mass transit is staggering. Part of the benefit of rail is that it can use dedicated facilities that are deconflicted. Autonomous vehicles still need to deal with red lights, pedestrians, cyclists, and limits on safe acceleration/deceleration. Here in Seattle our light rail system is hobbled because of non-grade-separated parts of the line - which despite having signal priority is restricted in its operation (station dwell times, # of trains in operation, train separation) because of conflicting cross streets. A central authority is NOT a panacea. With human drivers, lane density tops out at somewhere around ~900 vehicles per hour. Let's say automatic cars can somehow double that - to 1800 vehicles per hour. Even dedicated bus lanes can move 6000 people per hour. Forget Manhattan which is a beast of its own scale - look at Chicago mass transit which moves over a million people a day. You're sure you could replace the capacity of rush-hour Red Line trains at crush capacity with the surface streets? Really? Where would you park these cars? Where would everyone get in and out of the cars? (On/off boarding is the scaling limit for bus lanes - that alone is enough to sink your plan.) You do realize the irony in having faith that centralized coordination between autonomous vehicles will lead to these improvements?
- CamperBob2 10y ago
  Even dedicated bus lanes can move 6000 people per hour. But not where and when they want. Passengers-per-hour figures are simply measuring the wrong thing. Forget Manhattan which is a beast of its own scale - look at Chicago mass transit which moves over a million people a day. You're sure you could replace the capacity of rush-hour Red Line trains at crush capacity with the surface streets? Really? Where would you park these cars? Considering that there won't need to be as many cars, parking won't be a huge issue. Cars that spend most of the day and all night sitting in parking spaces are a waste of both resources and real estate. In an optimal scenario there wouldn't be a need for any parking spaces at all. Here's a thought experiment for you: take all the taxicabs off the streets of NYC, and replace them with privately-owned cars. Hell of a mess, isn't it? Nowhere to park between Boston and Philly. Now go the other direction, and imagine that every single passenger car that isn't a taxicab simply isn't there at all. It should be obvious that there would be plenty of room in that scenario, both on the streets and in the parking garages. Every single objection you raise is an example of "fighting the last war." You're pitting the worst aspects of the status quo against the best aspects of your favored solution. This happens time and again when these threads come up. Can you point to a single transportation expert who believes that centrally orchestrated single-occupancy vehicles are a solution for transportation capacity problems? No, but I'm less than impressed with the "transportation experts" I've encountered around here (Seattle area as well.) It seems self-evident that planners who devise fixed-rail systems with 25-35 year construction horizons while not even considering the arrival of autonomous vehicles are not competent at their jobs.
  - oasisbob 10y ago
    > It should be obvious that there would be plenty of room in that scenario, both on the streets and in the parking garages. No! It's absolutely not obvious. My biggest problem with your argument is that you're taking it for granted that streets can move as many cars as you think they can. They can't. For the sake of argument, I'm willing to entertain the idea that you can double throughput through automation, and that simply isn't enough for such a low-density form of transportation. Again - picture your system in Chicago where it moves 300,000 people into the downtown loop during the commuting rush-hour. Nobody owns any of these cars, so there isn't any parking to worry about. Fine. Where do these 300,000 people get in and out of their cars? Remember - bus lanes can't even scale past 6,000 people an hour per lane because of the need to get people on and off. Don't forget that these throughput numbers are under best-case scenarios, for smooth flowing traffic. We haven't even discussed intersections...