Hacker News Reader

Comment by Zambyte | Hacker News Reader

We should put self driving cars on tracks so they are always out of the way and have easily predictable behavior. Maybe we can even link the cars together for efficiency or something like that.

View on HN

You can further optimize the setup by not installing engines/motors in all of them. So maybe you have one car providing locomotion, with the rest following behind and designed for carrying.

That’s actually getting less common; pretty much all rapid transport and commuter trains are multiple units these days, as are an increasing number of intercity trains.

In Ireland, there are precisely two passenger routes still operated with locomotives, and there’s a tender offer out to replace one of them with a (really wacky; diesel, battery, _and_ overhead lines in two voltages!) multiple unit.

And all the power could just come from a few large centralized facilities that are super efficient. We could just use thin strands of metal to get it to the vehicles over head…

Of course, the maintenance on those wires outside of the city means that you'd make electric trains with large batteries on them instead.

https://evmagazine.com/articles/tesla-launches-first-all-ele...

I don't think I buy BEV trains to be honest. I'm struggling to think of a proper reason why they might be better compared to normal electric trains.

But the linked article is pretty light on info, so I'll reserve judgement till more info comes to light.

The economics work out where they’re pretty low-frequency (I think less than two an hour per direction is the usual figure).

They’re also useful as a transition technology. The DART+ project in Ireland will use them for one line which will have the frequency for electrification (8 trains per direction per hour) and is already partially electrified, but is going to take a while to fully electrify (due to low bridges etc); once it’s electrified they’ll then likely be used in low-frequency regional routes.

(The realised project will use 750 uniform cars, about 200 of which will have batteries.)

They are good for infrequently used track and places where overhead wires would be in the way, like that very Tesla employee shuttle on it's own track and container ports.

It's not the best way to go for mainline track and not suitable for long distance high speed trains.

Ireland is going to use a particularly unusual one for the Dublin-Belfast intercity route. It will have batteries, _and_ diesel generators, _and_ will run off overhead lines, in two voltages. The context is that parts of the line will take a while to electrify; it will initially run on overhead, battery, and diesel, then just overhead and battery as the lines are built out, and then hopefully finally just overhead.

If it's infrequently used, a dual mode diesel-electric can fill that use case today.

Expense is correlative to scale, likely it's cheaper to deploy pantographs than battery factories.

Why did India build a high speed freight corridor with overhead power when they could have used batteries instead? Because the quantity of battery to power the trains doesn't exist, and overhead wires do.

If we do all of that, then we won't need to train them to know how to operate in traffic. Perhaps we can give them a name in honour of that fact?

untrains!

It's tedious to see these same sarcastic comments on every self driving car story. Yes. Buses and trains exist.

When you link the cars together, they usually switch to a hub that's a 10-15 minute walk from your destination instead of your destination and the compartments are occasionally shared with unstable and violent people, which while possibly "efficient" in some metrics, are downsides that many people would rather avoid. Personal compartments are a real differentiating advantage.

“10-15 minute walk”

A quaintly American complaint. A 10 minute walk being an issue is very a learned helplessness my fellow Americans suffer from.

But unfortunately the 10-15 min walk is only possible in a couple cities. most Americans day to day experience of public transit is spaced out buses that don’t work well for single family sprawl and strip malls parking lots where walking is treated as undesirable. Car oriented rather than people oriented urban planning (or lack thereof) is the original cause.

It could be 10-15min where I am blasted by -10c wind in Boston or Miami torrential rains

Door to door shelter and climate control >>>>>>>>>>>

As someone who lives (and doesn't own a car!) in the Boston area, coats do wonders :)

I even got a heated jacket this year! Talk about climate control.

Because the weather in walking cities is perfect?

violent unstable people aren't inherent to cities.. they're inherent to places that refuse to spend any money on social work/housing/and enjoy punishing people

I would rather pick to not be subjected to them than to be subjected to them. NYC spends over 40k/homeless person and I still have to be subjected to them, even though I paid enough taxes to wash my hands of the issue morally

All public transit is at least an order of magnitude safer than driving a car. 10-15 minutes of walking is called being an inactive human. I promise it won't hurt you (unless you get hit by a car).

Maybe we can do away with the expensive battery if we feed power to these cars using overhead cables.

At this point overhead cables are likely many orders more expensive.

Buses in Paris run with IIRC 60kWh battery and pantograph charger at every other station. Packs (not cells) recently dropped to below $100 kWh. At $6k thats probably what city pays for couple of replacement seats (gold plating et all).

In the original Sim City, having your city entirely use tracks instead of roads was superior because there was no traffic congestion from tracks

And less pollution from cars.

If you're happy to put those tracks on every road, sure. I wonder why no-one's bothered with that before.

Sorry if you're playing in to the joke, I can't tell. Streetcars / trams were widely deployed before they were ripped out for the car, driven by lobbyists interested in selling cars. Wondering why no one has bothered with that is starting from a false premise, because people have bothered with that.

I'm well aware that there are multiple options for public transport, but none of them are actually as flexible or as far reaching as cars/taxis. To me this 'but why not trains' on every article about self-driving cars is a tired meme that fails to address that these are not equivalent options. I might as well say "Well, why don't we get rid of these expensive rails and fixed timetables and just lay down some cheap concrete and let people navigate how they want" in just as condescending a tone and be equally as unconvincing.

It shouldn't be all black and white (either 100% car use or 100% public transport use).

If you're rural - of course this probably doesn't apply.

If you're suburban - "park and ride" type of thing solves a lot of problems in western Europe already. Drive to nearest hub, hop on a train (that is included in your parking ticket) that has bigger bandwidth comparable up to a 30 lane highway[1], also don't worry about parking in dense downtown as a benefit.

If you're urban, city planners should plan public transport network dense enough so you could walk - at worst do "park and ride" thing again.

Of course there are cases where car still may be fastest and most convenient way to reach your destination (e.g. if you're suburban and need to go to other suburban town), but in big cities (individual) car travel should be a minority.

Compare Japan's, China's mega cities. Whole countries like Netherlands, Denmark, Belgium, to LA, SF or other USA's mega cities. It just falls to the Onion trope of `'No Way to Prevent This,' Says Only Nation Where This Regularly Happens`.

[1] https://en.wikipedia.org/wiki/Route_capacity#/media/File:Pas...

The key issue is that cars have _vastly_ lower capacity per meter than mass transit. For most large cities, there is simply not enough road for that to work, nevermind parking.

There are car lobbyists of course but the streetcars in LA at least were put there by housing developments to sell suburban homes before most people owned cars. Once the homes were sold the corporation that built the rails had no incentive to maintain them, and eventually they were spun off and went bankrupt (of course competing with cars didn't help)

Nor did the fixed price controls they were often saddled with. It seems that politicians are congenitally completely incapable of considering inflation indexing as a concept when they are writing laws.

Street cars are a red herring anyway. Because street cars don't maintain anywhere near the same number of routes as free-form roads. It is a routing problem still, and railed vehicles perform much, much worse at it, which is why they need to be time multiplexed with rail schedules.

> I wonder why no-one's bothered with that before

Streetcars?! In San Francsico?!?

How long do you think it will take you to get across town if you have to wait through a stop on every block?

Better leave now for you doctor’s appointment tomorrow and I hope you scheduled three days off from work.

Maybe even put them on steel wheels on steel tracks, to make them more efficient.

Have something like metro (maglev trains) too as they are more efficient than steel wheels on steel tracks.

Public transport for things like metro/trains/trams/buses are honestly underrated.

Fast forward to blackjack and hookers.

Slot cars at the grown-up level.

Rugged American Individualism and Capitalism doesn't allow us to have things like that. We must always be in our individual bubbles away from the filthy poors.

Reply on news.ycombinator.com