Self driving car tech will be the only method that can provide a hundred fold decrease in driving fatalities. Slowing down progress has a cost too.
Sounds like it would even be better in the long run.
But of course you weren't talking about trains.
I see this sentiment a lot on HN that self driving cars are going to fix everyone's transportation woes, but I'm not convinced that they will. For example, they're never going to be particularly efficient at really high speeds, due to tyre wear (due to heat) and air resistance (which can be reduced by driving in a convoy, but not enough). Rail (or maybe hyperloop, who knows) will still be much more efficient for high-speed travel, not to mention much faster. So maybe the cars will all be going 40% faster on highways than nowadays, which is nice, but still only half of what rail can do, and even less for hyperloops.
I don't buy the "it's gonna fix everyone's commute", either, because at the same time it's supposed to fix parking. So now you have loads of cars driving out of the city to park at the same time as you've got just as many driving into it. Sure, vehicle-to-vehicle communication and superhuman reaction times will allow for increased density on roads, but is it enough to offset the increase in traffic? And is the increase in miles driven and resulting road maintenance cost factored into the cost calculations?
Damn right I want cars to drive themselves, and it's going to be fantastic. But I don't think autonomous cars are the panacea that many seem to see in them.
Many light rail services e.g. BART and the London Underground are completely crazy at rush hour and there are many obstacles to increasing frequency. A big challenge of self driving trains is ensuring they are able to stop in time if an obstacle is present, and this relies on fairly similar technology to that of driverless cars. Self driving cars would reduce traffic because they would reduce accidents and allow cars to sort themselves into slots automatically rather than waiting at traffic lights.
You have a good point about rush hour traffic being increased by cars driving outside the city to park, although cars could park more efficiently in city centres if multi-storey car parks didn't need to allocate space for humans.
The Underground (and commuter rail that feeds into it) carries a vast number of people every day. There's just not enough road space to get that many cars in and out, even if they were 2x or 4x more efficient.
If you want to fix the Underground (although it works fairly well so it's not clear why drastic changes are needed) you need to start thinking about buses and bicycles, staggering working times to avoid rush hours, moving jobs outside the city so people don't have to commute in at all, that sort of thing. None of those actually needs AI.
Self-driving cars (and especially self-driving buses and minibuses) can certainly be part of the solution, but they're not the solution.
The population of London continues to increase. Central, Northern, Jubilee lines are often difficult to get on during rush hours, and even harder to stay on. And that's in the winter, summer time's a whole other ball game...
Self driving cars are certainly not the solution, but that's not to say there's not plenty that needs fixing on the London Underground.
https://www.youtube.com/watch?v=FOF_XIylzS8 still rings true, albeit with less BK these days than before.
That means that to get competitive flow with buses, self-driving cars need to deliver a tenfold improvement in flow. Since in traffic cars are quite tightly packed already, you probably can't get much from putting them closer together, so even if self-driving magic gives you two doublings of flow on its own you still need to more than double the speed limit to compete. I can imagine this working only on roads dedicated to self-driving vehicles, with no pedestrian crossings, so now self-driving cars benefits only materialise if they eat up a chunk of the public space.
You might get a bit of improvement from vehicle sharing as well, but it seems like a really complicated way to attack a problem that already has an OK low-tech answer, at least in high density areas.
Where I live the census says that about half the commute journeys in the area are less than a few miles, for which cars of any sort seem ridiculous to me, for the able bodied. For those who aren't able bodied or have a long journey all the able bodied car users on short trips are using up a scarce resource that they need!
Throw in the health benefits of active transport, and the health cost of particulate emissions (still a problem with electric cars, since a decent chunk comes off tyres and brakes) and it looks like a wash to me. Then again I am one of those awful bike people, so maybe I miss the point.
[1] Litman 2017, Brun & Vuchic 1995 etc.
There are a number of US cities that get most workers into the urban core besides NYC despite poor to middling infrastructure at best, but driving infrastructure dwarfs everything else, bike lanes are added only to diet roads usually (resulting in shitty lanes), and most areas see 60% to 70% of their land tied up in (mostly empty) parking, which is a disaster for every mode of transport.
However, each person who uses a car creates some external costs (a high traffic factor / unit of person-flow) which are borne by all the other road users. Once people choosing the "defect" strategy (cars) have enough numbers, the "cooperate" strategy (not cars) gets broken for other solutions that use the road network, so the system fails to a bad equilibrium if there are enough defectors in the population.
(I'm not a fan of cars; I don't drive one myself. But I don't expect people to accept any less convenient and flexible solution.)
Mass transit specifically trains have serious problems I don’t think there are solutions for. The first is that they make centralized points of failure. Broken trains can bring a whole city to a halt. The second is they are the perfect germ delivery system.
It's not as easy as you make it sound. Americans still want cars.
America is a vast land compared to European countries. Public transportation can only go so far. Some American suburbs stretch more than 80 miles out of major urban centers.
This, of course, is a solvable problem.
(It has nothing to be with how big the US is, it has to do with how US communities are deliberately engineered.)
Dense cities are cheaper to live in, cost less to maintain for everyone involved, and give people back time that is currently stolen from them during the average commute. You also end up with better infrastructure, lower taxes, and usually a healthier and happier population in dense cities.
Suburban and exurban slum development with 1 to 3 stories and a 1 to 2 hour commute is destined to die, its just a matter of how and when. Detroit is one failure mode, while Livingston, TX is another (tax base could never support the infrastructure built), though the latter case is very common.