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> There's been a lot of tax breaks/money that goes into these programs too, and that's the tragic thing, since that funding should be going to known solutions:

> There's been a lot of tax breaks/money that goes into these programs too, and that's the tragic thing, since that funding should be going to known solutions: public transportation (trains, trams and express buses). Citation needed. > Even if you had a full-autonomous only Interstate where each car could be fully loaded and ride bumper-bumper at over 100kph, it wouldn't even begin reach the carrying capacity of currently existing fully autonomous subways systems like those in Singapore. Citation needed.

A2017U1 8y ago
From the comment guidelines: > Please don't post shallow dismissals, especially of other people's work. A good critical comment teaches us something. Handling 30k passengers per hour is manageable for most rail lines around the world. Torontos Bloor line does 500,000 daily. Similarly highways are constrained to their own maximums per lane, and counterintuitively raising the speed limit doesn't help. 1500-1700 vehicles per hour is a fair estimate. http://buckholztraffic.com/UNF/Data%20Analysis/2%20Lane%20Highway%20Notes.htm http://buckholztraffic.com/UNF/Data%20Analysis/2%20Lane%20Hi...
- illumin8 8y ago
  He posted unsubstantiated claims about tax breaks (I'd like to learn where there are tax breaks for autonomous vehicles) and a claim about trains having more throughput than an interstate with cars fully loaded moving 100kph bumper to bumper. Asking for citations might be a shallow dismissal, but stating hypotheses without facts to substantiate them is also shallow.
  - dang 8y ago
    That's true, but taking the thread further in the wrong direction only makes it worse. There are other ways to ask for more information, that open discussion up rather than stiffening into confrontation. Please post in that spirit instead.
  - djsumdog 8y ago
    Did you click on the link? It goes the the article I wrote, which has a ton of sources at the bottom.
blattimwind 8y ago
A train or subway car can carry at least 10 people per meter vehicle length, while a car is usually some four to five meters long and usually carries only one or two persons. Of course, the comfort factors are decidedly different.
- computerphage 8y ago
  That's true, but it doesn't resolve the disagreement. Consider the fact that trains aren't infinitely long, and so they have to slow down everyone to let some passengers off. There's an idea where a train "car" is boarded and accelerated separately then joins the rest of the train while it's moving, but this approach is rarely implemented for many reasons.
  - com2kid 8y ago
    > and so they have to slow down everyone to let some passengers off. So do roads, slow downs happen when cars get on or off of highways. Going from a road with a high speed to one with a lower speed, if those roads are at capacity, will always result in a backup. Off ramps serve this purpose of course, they basically convert cars going at 60mph into traffic going 30mph through stop lights or some other sort of flow control, but if the roadway is at capacity (as many major cities are), that off ramp as a flow control mechanism falls apart and cars pile up onto the freeway. The math is unfortunately independent of self-driving cars. If every car is self driving capacity does increase, cars can self coordinate and some of those stop lights become unnecessary, but if 100 cars want to get onto a road that has room for 20, someone is going to have to wait! Subways naturally don't have this problem!
    - stickfigure 8y ago
      This argument seems to compare 1 interstate hwy to 1 rail. In fairness to the autonomous vehicles, there's many road routes to most places. Road infrastructure costs a tiny fraction of rail infrastructure. Roads also allow for multiple lanes. This allows for somewhat degraded service when something goes wrong; a train stopped on the tracks blocks everything. With multiple lanes, roads can be maintained while still in service. Every subway struggles with maintenance windows. I'm not saying one is always superior to the other - trains have their niche, but it's a niche that will never be as broad that of autonomous cars.

A2017U1 8y ago

From the comment guidelines: > Please don't post shallow dismissals, especially of other people's work. A good critical comment teaches us something. Handling 30k passengers per hour is manageable for most rail lines around the world. Torontos Bloor line does 500,000 daily. Similarly highways are constrained to their own maximums per lane, and counterintuitively raising the speed limit doesn't help. 1500-1700 vehicles per hour is a fair estimate. http://buckholztraffic.com/UNF/Data%20Analysis/2%20Lane%20Highway%20Notes.htm http://buckholztraffic.com/UNF/Data%20Analysis/2%20Lane%20Hi...

illumin8 8y ago
He posted unsubstantiated claims about tax breaks (I'd like to learn where there are tax breaks for autonomous vehicles) and a claim about trains having more throughput than an interstate with cars fully loaded moving 100kph bumper to bumper. Asking for citations might be a shallow dismissal, but stating hypotheses without facts to substantiate them is also shallow.
- dang 8y ago
  That's true, but taking the thread further in the wrong direction only makes it worse. There are other ways to ask for more information, that open discussion up rather than stiffening into confrontation. Please post in that spirit instead.
- djsumdog 8y ago
  Did you click on the link? It goes the the article I wrote, which has a ton of sources at the bottom.

blattimwind 8y ago

A train or subway car can carry at least 10 people per meter vehicle length, while a car is usually some four to five meters long and usually carries only one or two persons. Of course, the comfort factors are decidedly different.

computerphage 8y ago
That's true, but it doesn't resolve the disagreement. Consider the fact that trains aren't infinitely long, and so they have to slow down everyone to let some passengers off. There's an idea where a train "car" is boarded and accelerated separately then joins the rest of the train while it's moving, but this approach is rarely implemented for many reasons.
- com2kid 8y ago
  > and so they have to slow down everyone to let some passengers off. So do roads, slow downs happen when cars get on or off of highways. Going from a road with a high speed to one with a lower speed, if those roads are at capacity, will always result in a backup. Off ramps serve this purpose of course, they basically convert cars going at 60mph into traffic going 30mph through stop lights or some other sort of flow control, but if the roadway is at capacity (as many major cities are), that off ramp as a flow control mechanism falls apart and cars pile up onto the freeway. The math is unfortunately independent of self-driving cars. If every car is self driving capacity does increase, cars can self coordinate and some of those stop lights become unnecessary, but if 100 cars want to get onto a road that has room for 20, someone is going to have to wait! Subways naturally don't have this problem!
  - stickfigure 8y ago
    This argument seems to compare 1 interstate hwy to 1 rail. In fairness to the autonomous vehicles, there's many road routes to most places. Road infrastructure costs a tiny fraction of rail infrastructure. Roads also allow for multiple lanes. This allows for somewhat degraded service when something goes wrong; a train stopped on the tracks blocks everything. With multiple lanes, roads can be maintained while still in service. Every subway struggles with maintenance windows. I'm not saying one is always superior to the other - trains have their niche, but it's a niche that will never be as broad that of autonomous cars.