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Comment by nvahalik | Hacker News Reader

> Autonomous vehicles would fare better, he said, "if we were to modify roads and have certain sections that are well mapped and kept clean of refuse, and nothing unusual happens and there's no road work."

He's talking about trains and other modes of public transit. Which makes sense. Of course, even those have occasional problems.

Personally, I'd love to simply find a way to make "mass transit" more workable.

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I wonder if anyone’s considered making a kind of modular way for vehicles to connect to something like a train.

I can think of two examples.

In LA there are busways that are built on former train paths. When they need to divert for whatever reason (road repairs, special event routes, etc) they can just make a turn and act like any other bus. Something like the Hyperloop car carrier could work here or at the very least an expansion of bus ways could provide train like access with a lower infrastructure cost.

Amtrak will also let a certain number of vehicles onto some of their train lines. I don’t know how well that works, but it seems like for a well run popular route you could have a ferry like experience.

Similar to the LA example -- the O-Bahn in Adelaide: https://en.wikipedia.org/wiki/O-Bahn_Busway

Not being sarcastic but cars can go “on” trains.... checkout EuroTunnel for example

like some sort of train that a car could drive onto and be transported?

This has existed for years.

More crazy. Something they either create by linking up to each other or drive onto but can drive off of at speed and any time. Needs to be immediate to join and leave or people won’t use it.

Or it has its own lane, and if you don’t use it, you sit in a traffic jam watching the people who do use it whizz past.

Not everything has to be instant gratification catering to your every need or else you’re buying a helicopter :-)

Road trains don't really give you much savings from a traffic jam unless there is something else that prevents most people from using it. Single passenger cars take up a lot of space. Getting cars/people out of the train will slow the whole thing down where they need to leave the "fast?" lane for the traffic jam to get to their exit.

Unless you are talking about all new freeways usable only by road trains. However at that point putting down steel rail is cheaper and can handle an order of magnitude more people for the investment.

Road trains could give us greater efficiencies from aerodynamics, and if used in dedicated lanes, could also give us something almost as useful as autonomous driving with much less work.

As for steel rail, gosh, I really wish there was a way to make the politics work in North America.

While the theory of road trains is sound, in practice they cannot work as well because of other theory. Getting into/out of a road train is hard. If there is a traffic jam in the other lane, the entire lane is limited to the traffic jam.

Road trains save some space, but they don't solve traffic jams (which already have cars bumper to bumper). There is no way around the fact that cars need a lot of lane space to work well, even in road train model. (steel rail solves that by packing humans tighter, while giving them more space)

Bike and scooter racks on a train. Rental kiosks at stations. This is a solved problem, it just requires investment.

We have those; they’re called parking lots and they’re usually found at commuter train stations.

Snark aside, I don’t think it makes much sense to try to merge cars together at high speed. It’s a very complicated maneuver, requiring all cars behind the intended merge point to back up and make room, and the consequences of an accident have unlimited catastrophic potential. We could see hundreds of cars destroyed in a massive collision.

Besides that, the costs seem astronomical: actually developing the technology, making sure all car manufacturers comply with the standard, and replacing every single car on the road with a compliant model. Wouldn’t it be much easier to put all of that money into building high speed railways? We’ve already perfected that technology.

The biggest issue is trust. I maintain my own cars: I trust myself, but do you trust me? I don't trust some of the professional mechanics that work on cars. In the current scheme we are told to maintain a large enough following distance that this question don't matter: no matter what happens in front of you, you can still react in time to recover. (You will not that the vast majority of drivers do not maintain this following distance) In a raid train situation all cars must be maintained to high enough standards for the most risk adverse person.

In trains we already have standards, and have developed schemes to ensure that cars are maintained to standards.

Note that trust above needs to account for the terrorist trying to kill people. It is debatable what systems works.

Docking wouldn't have to occur at high speed, or moving at all, for this to be useful. For example, I live in Massachusetts and I have a car full of gear that I'd like to have for my vacation in New Hampshire or New Jersey or Michigan. So I drive down to the local train depot, where my car is docked (or even just loaded onto) a train, I get in the passenger compartment, we're reunited at the other end. Already more efficient than driving, and more pleasant too. Now start adding tweaks like loading only the passenger compartment, which is already a separate thing in electric vehicles. Or running rails along one lane of existing highway, with docking/undocking at existing rest areas. Once the basic "dock instead of driving" idea gets established, it's possible to iterate on it.

I recall Popular-Science-ish illustrations of systems like that where you’d drive onto the freeway and your car would hook into a chain of cars to be driven to a “stop,” where you could unhook.

If I understand it correctly, we are just now experimenting with something very like that for trucking, where multiple trucks can convoy, and the systems communicate with each other so that all the vehicles in a convoy adjust their speed simultaneously.

Wasn't this part of the Hyperloop project idea in LA? You drive to a specific parking spot, the vehicle gets lowered to a tunnel, then the tunnel takes you to wherever you need to go.

I think this is a really neat idea. Imagine cars arranging themselves and coupling into a train and then seamlessly decoupling as they need to exit. That would save energy (air resistance) and be a more efficient way to move more cars down the same piece of road faster. It also removes the lost time of intermodal transportation.

No idea if it's practical.

If you need to rely on the customer vehicles themselves for any part of the train's operation (wheels touching the ground, coupling, electrical connections...), it's going to be extremely difficult. Railways have strict requirements for inspections, etc. of customer cars—one malfunctioning car can be catastrophic (if a coupler malfunctions and lets go, for instance).

If you're not relying on the customer vehicles for any part of the operation, you're basically describing existing auto-rail operations. They're not extremely common, probably because they're a terrible waste of space compared to traditional passenger rail cars.

Our goal is to move people and goods around—not extra vehicles.

> Personally, I'd love to simply find a way to make "mass transit" more workable.

It's very workable already. Give it priority and separate lanes where possible, consider giving them exclusive use of roads in some areas, prioritise frequency over speed, maintain the vehicles regularly and replace them eventually. Finally, provide dedicated on-demand transport for people with special needs. The end. It works.

> > Personally, I'd love to simply find a way to make "mass transit" more workable.

> It's very workable already. Give it priority and separate lanes where possible, consider giving them exclusive use of roads in some areas, prioritise frequency over speed, maintain the vehicles regularly and replace them eventually. Finally, provide dedicated on-demand transport for people with special needs. The end. It works.

Many of the things you list are missing in mass transit systems across the US. That deficit being filled would make the system workable for many more people. It's s likely that workable was a poor choice of words and a more apt statement would be something along the lines of, "Mass transit as it is currently deployed across the United States requires a number of fixes to make it a more viable daily alternative."

One more important aspect: cost. In my country mass transit is bizarrely more expensive than private.

I was thinking more of a standardized type of super-regulated road that was only accessible for self-driving cars that could know about its status (road works, accidents etc) using a standardized API. Only vehicles certified to use the API correctly could enter it.

E.g. on normal roads a Tesla would drive as it does now with some driver assistance, but there would be special stretches here and there for only self driving cars where they could be autonomous.

I didn't read anything in the article to suggest he's talking about trains here. It looks like a reference to dedicated lanes, etc, for autonomous cars.

> I didn't read anything in the article to suggest he's talking about trains here. It looks like a reference to dedicated lanes, etc, for autonomous cars.

The parent likely means that the modifications required are the trappings of trains.

That is because he isn't visionary enough to recognize what he is talking about. Everybody has their blind spot I guess. (Come to think of it I wouldn't have realized this myself without being told)

Mass transit would be more workable if we simply built more and our autonomous vehicles could drop us at the station then return home.

Indeed this is really one of the best solutions. Light rail, buses, etc. taking people to and from businesses, restaurants, shopping, etc. and have autonomous vehicles traveling from residential areas to and from stations.

Unfortunately, when most people talk about autonomous vehicles they want personal autonomous vehicles. I really don't see the point of this if I'm not actually going to be driving. The fun of a vehicle is driving it, not riding in it. If it is autonomous, I don't want to own it and pay the upkeep.

Personal autonomous vehicles make sense for anyone who will do the majority of their daily travel in an autonomous vehicle. If you can take transit for most daily trips the vehicle is for things like getting a load of lumber that transit can never serve - these are rare enough that renting (at $100/day) is a better deal for most people.

If it is a daily trip, there isn't that much opportunity for car reuse. Rush hour is call an hour for a reason: most people travel at about the same time. Those who are traveling in a different part of the day tend to have different patterns such that they would need a different car (it needs car seats for the kids...)

If you have a luxury car, shared might make sense because you don't care about upkeep costs. However if you are cost conscience a 3 year old car that you keep for ~10 years is well known to be the cheapest way to go. These economics won't change: people who want a luxury car will demand the shared car be fairly new and well maintained. People who want the cheapest will still buy their own because they can guarantee the cheaper ride.

Don't overlook the advantage of knowing your golf clubs are in the trunk waiting just in case you can take an afternoon off for a round. Shared cars won't give you this, if anything like it is for you.

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