An autonomous car can travel on both normal roads, and in an autonomous lane. Roads are everywhere -- there's a road leading up to most people's place of residence.
Trains rely on tracks which are not as common as roads. Trains are also not owned by individuals. Most people do not have a train station outside of their house.
A train can move more tonnage (see people) per unit of energy (kWhr/gallon of diesel/etc.) Than almost any other mode of transportation (gosh darn sailboats and barges being so efficient!) .
So why have 100's of electric motors and separate batteries to move people, when you can skip the batteries and have an electrified third rail and just an engine or two running a train for those hundreds of people.
Guess where the two passenger lines that come even vaguely to profitability are?
The population of the US is very coastal, which doesn’t map well to a hub and spoke system like rail. Contrast with Western Europe where A -> Paris/Berlin -> B is probably reasonably close to a straight line.
I'm all for the US pouring money into rail, but the fact is that we're _very_ bad at big infrastructure projects right now. That's not to say that we can't get better though.
You need to think about it on two metrics;
(1) density of transport; how many people per unit volume
(2) power to # of passengers.
On both counts trains are vastly superior to almost all other modes of transit other than boat.
But parent's comment was aimed at the one lane for self driving cars comment.
So I don’t see how you comment could apply to it. Yes we have roads leading up to almost everyone’s house. But in the case of a dedicated self driving lane proposal it would be as impractical As giving everyone a railway track leading to their home.
> Trains are not owned by individuals.
Exactly. So instead of building infrastructure to improve moving a few people at a time, improving infrastructure that helps move a few hundred at a time seems like a better investment.
Planes aren't either, what's your point? That people who need to go somewhere should be priced out of using _public_ infrastructure and require a personal investment currently in the tens of thousands for the cheapest autonomous cars?
> Most people do not have a train station outside of their house.
People have feet or a wheelchair, bicycles are a thing, trams and buses exist have you ever even been outside of suburbia?
> Planes aren't either, what's your point?
My point is that the comment I replied to implied that trains can replace cars. Trains cannot replace cars because they are a form of public transportation, which cannot easily replace cars.
> That people who need to go somewhere should be priced out
This is quite the leap. My comment did not argue the merits of either, merely that trains would not be a very good replacement for autonomous vehicle lanes.
> have you ever even been outside of suburbia?
This isn't useful to your argument. Why are you resorting to a personal attack?
> so they would not be a very good replacement for autonomous driving lanes.
Railways world-wide: 1,400,000 kilometres.
> Why are you resorting to a personal attack?
Are you seriously considering my putting out there that your personal experiences might influence your arguments to the point of not being credible a personal attack?
If it weren't because of price, I'm sure everybody would prefer flying private.
Flying commercial is pretty much as awful as it gets.
Oh, OK, the only reason we shouldn't move the 10,000 daily passengers between LAX and SFO in 10,000 planes a day is because of the price.
/s
Also, who implied that railways need to be privately owned?
