I would second the undo button and the track planning feature. Also the cargo warehousing seems very useful, especially if this was coupled with barges.
I would add a need for more complex orders such as ‘collect nothing’ or ‘collect a certain material only’.
I would also love to see more industry and perhaps some individual buildings like a house you can situate as your home in your town. I would also love to see some events that can happen that you need to react to, and of course AI competitors.