Firstly, yes, electric locomotives. Using something like Immersive Engineering, or Redstone Flux to act as a power supply, it sounds very good to me. Electric trains wouldn't need to "warn up", and could be recharged quickly ( or even, electric rails, that allow the train to charge/not use its internal power, while on said rails ). This would be very useful for someone like me. I use Immersive Railroading for things like my subway systems, however, the fuel system has thrown a few wrenches in my way, such as trying to automatically determine if the train needs refuelled, and then diverging it off the main tracks, to an automated filing station.

Secondly, automation. I haven't gotten too much into the automation yet, however, based on quick overviews, I noticed some things that seemed to be missing. I didn't see documentation too much on what exact info the OpenComputer API supports. The biggest things for me, are these; an ID. I need to be able to track which train when over my sensor, for automatic arrival-time prediction, and automatic railway routing ( because train 0x2F needs to make a right to merge to RED-LINE, whereas train 0xB1 needs to continue straight past two more junctions, until it's supposed to merge to BLUE-LINE ). It also should be able to view the fuel and temperature level of trains. I need to determine if a train can continue its route, and a big thing with that, is it's fuel level. Of course, you could do estimations ( I fulled this train just now. It should be able to travel about three hundred rails before needing refused again ). Since this paragraph is becoming long, I'll briefly list the other information things. Weight/Mass. I'm sure the mod has some system that make it so more carts => slower stopping and accelerating. That's important to know, so I know when to start braking the train so it will stop at the station properly. Maximum speed. For some railways, I have "speed limits", either minimum, maximum, or both. Usually both, because it's automated. Some rails are faster, for long-distance travel, and a train unable to reach that speed going on it, would cause some major issues.

Tickets. Sure, sure, you could use some sort of economy mod, with a gate system that takes money. However, I think it could be employed very nicely on this mod. Allow for the person in the locomotive to "claim" it, where they can do things such as locking the locomotive ( the engine part ), and whatnot. They can also require tickets. Maybe they must be signed by someone specific or something ( OC could be really useful for this, making it so only specific computers with a password or something can print tickets ), and then for a user to go into a train, they must click it with a ticket. Simple, and I think it could add a small enhancement for survival servers. ( Of course, just simply adding some sort of configurable support with economy mods could be really good - not as good, but good )

Lastly, what I actually initially meant to write this about, but got sidetracked ( haha ) - Better documentation on the trains. I rarely use the trains frankly. Mostly do to their larger size, it makes it harder to work with sometimes. However for automative systems like subways and large scale railways, they are very useful. Unfortunately, knowing info about them isn't very easy. In-game you can see the weight, speed, traction, gauge, and horse power. However, something that I think is really missing - things like the fuel consumption speed ( assuming it's not all uniform, if it is, a simple wiki page on how to calculate fuel consumption would be handy ), and what sort of fuel it takes. I'm not saying in-game, but I am saying at least here on the GitHub wiki. For me, that is really important, because I need to make sure all my engines use the same fuel, otherwise my automative fuel stations would be thrown off, and require a ton more calculating and work.

Sorry for the very very very long entry. For the most part, I must say I like this mod. Some things I don't, of course, but the good far outweighs the bad. These are just the main things that stick out to me.