Make basic Trains and Wagons need Vehicle Parts I to build instead of Vehicle Parts II. That would make trains much more accessible at early game. Who need glass for a steamers, if you don't need it for Pickups?!

A mod to move whole basic Trains tech before Steel could be even better. Maybe after Advanced Logistic Control tech? Just Trains, not Long Trains, though. For example, Rails could have separate recipe for 8 Wood + 8 Iron instead of 8 Concrete Slabs + 4 Steel at Assembly II, and small Wagons would need Iron instead of Steel.

I generally exited about the prospect of having Basic Trains available much earlier. I would not need hundred of tiny cars to haul bulky stuff too far, hehe.