I’m writing this up in more detail elsewhere, but…
- As we move to higher robocar density we can get a lot more traffic capacity on the roads, especially with half-width 1-2 person vehicles. At rush hour I’m talking 15x more capacity! Even more if you use vans, but would you use vans in that case?
- Again, in that future world where you can make a small light car, a 500lb car that doesn’t need to worry about being crushed, and the sensors get cheap due to Moore’s law, you can make that vehicle really cheap. Though I agree, it’s hard to compete with a transit pass. Though that pass only exists because the whole transit system is massively subsidized. But it’s not hard to compete with a regular fare, or with the real cost of a fare.
- For rush hour, I can see the use of vans and buses. But the problem is there is no desire for them outside rush hour. If the private trips are so cheap, and the roads not that loaded, who will wait for a van to save a tiny amount of money? And in that case, what pays for the vans and buses just at rush hour? Perhaps a very high congestion charge.
- Turns out studies show the peak is not nearly as high a peak as you think. Rush hour isn’t even the peak travel time, it’s lunch hour!
- Robotaxi cost is by the mile. Sitting around costs almost nothing, just the parking cost — if there is a parking cost for something that can go anywhere to wait, even in front of a fire hydrant. So yes, 5 small robotaxis cost a lot less in terms of equipment and fuel than a city bus with 5 people on it.
- Dedicated ROW is useful but quite wasteful today. We put in a rail line and there’s one train on it every 15 to 30 minutes. It sits empty most of the time.
- If you want to do the train, I think it works fairly well, actually, if you design your train station for it. The train pulls up with 5 60’ cars. Lined up on the platform are 22 12’ long robocars. Or possibly 44 on both sides, or if you do this right, 88 because they are 4’ wide and you get two abreast. The first 120 passengers (some are in pairs) get into the cars, takes about 45 seconds, and off they go, in parallel sort of like another train, but this train immediately splits apart to go to all the 88 destinations. As they leave, 88 new cars follow them in and stop, and the next round of passengers moves in.
- Don’t like that? Well, have the people move off the platform to special robocar platforms one level below. The robocar platforms are packed densely with cars. Here we have extra lanes so cars don’t have to wait for the car in front to move so it’s a constant flow.