Comment by cedws
1 day ago
Trains shouldn’t even be manually driven in 2026. We have self driving cars now which is a way harder problem to solve. Relying on a system of signals and driver attentiveness is archaic.
1 day ago
Trains shouldn’t even be manually driven in 2026. We have self driving cars now which is a way harder problem to solve. Relying on a system of signals and driver attentiveness is archaic.
LZB does cab-signalling and continuously supervises speed and braking curves. Combined with AFB it can accelerate and brake automatically to LZB targets. So regular operations are already partly automated (and have been for a long time). The system already doesn't rely on perfect driver attentiveness for safety. The driver should still watch the track ahead, but trains usually can't stop within line of sight anyway, so for separation we have to rely on the signalling system.
Drivers are absolutely still needed for other parts of the operation though, like working stations, shunting, and perhaps most importantly handling irregularities. Faults can happen and you don't want the train to be stuck out on the track for hours. Instead, it makes so much more sense to either fall back to lineside signals (often accompanied with a point-based train protection system) or driving within line of sight.
> Trains shouldn’t even be manually driven in 2026
Potentially, but the point is that signallers should physically be unable to allow trains to proceed, and drivers should physically not be able to override them. British signalling from the 1800s has physical interlocks; this isn't a matter of manual versus automatic train operation. It is clearly systemic.
How do you pass a defective signal then? How do you couple a second locomotive? How do you add cars?
Driving a train and driving a car are two completely different challenges.
If signaling worked properly then it wouldn't matter whether the train was driven autonomously or not, the "problem" becomes trivial. Establishing and continuously verifying that signaling is working properly is the hard part.
Without signaling you're limited to crawling speed just like humans are when they don't have any signalling .
Yeah, if you completely ignore availability as a problem. The state of the art self-driving technologies we have today only work in some conditions, some of the time.
The reason vehicles are still driven manually is because humans rely on transportation every day, all of the time.
We do not have self-driving cars in all environments that clear the necessary security regulation! Also the socially accepted number of deaths due to trains is way below that for cars. The current accident is just a Tuesday for car traffic. (Spain recorded 1785 road deaths in 2024[1], that's 4.9 per day) Detecting objects (and future objects!) on a train track is still a hard problem.
The current system is basically that the train is driven both automatically and by a professional attentive driver at the same time. Changing it to just the automatic system is going to reduce safety. Also the real world is way to messy to reach acceptable availability rates with only automatic systems.
[1] https://www.itf-oecd.org/sites/default/files/spain-road-safe...
> Detecting objects (and future objects!) on a train track is still a hard problem.
In this case the “object” was another train. That’s not the “hard” part of the problem. This sounds like an apologist comment.
What difference does that make, genuinely?
Are there systems that can warn drivers and prevent collisions without external signaling, like ACAS?
Yeah, that's a solved problem. Did you even read my whole comment? I answered why "just use the system from self-driving cars" wouldn't work and in fact would be less safe than the current system.
What's the stopping distance of a high-speed train at full speed? I don't know, but I bet it's kilometers, not meters.
Detecting an object on the tracks 2 km away (say), as opposed to beside the track at the same distance, is in fact a hard problem. The tech used in self-driving cars is not going to solve it.