1. Elevators, for humans and vehicles.
2. rotating train platforms, The train platforms that spin so you can have a train yard if wanted, used for organizing and multiple train routes, POSSIBLY controlled by a control room similiar to suggestion 8.5.
3. A change to liquids as in, liquids have to be transfered through pipes. (similiar to factorio, if possible)
4. New Vehicle suggestions and ideas:
4.1 -- tanker car (Train) - to carry liquids raw liquids from one place to another -- Drum liquids can be transported with normal storage cars. (If raw liquids are added)
4.2 -- Vehicle car (Train) - a way to transport your vehicles on a train, like a flatbed tow-truck.
4.3 -- Passenger car (Train) - for train to transfer passengers from 1 place to another without having to stand ontop of train or driving it.
4.4 -- Hovercraft (Vehicle) - also able to hover on land and over water if possible, doesn't hover high, if jumped off a high area falls slower than a normal vehicle negating fall damage.
4.5 -- aircraft (Vehicle) - some sort of flying vehicle that can also be automated (futuristic, very late game vehicle)
4.6 -- Jumping car (Vehicle) - similiar to the hopping car from the playstation 2 game jak3, uses suspension (with compressed air) to launch the car up.
5. farms/crops (that can also be grown indoors, layers and automated, as they exist in real life) [probably already suggested by another person]
6. Garage style doors, so people can make a garage for vehicles (used with gate wall) [could possibly be already planned]
7. able to build your own hub in your factory, basically like the M.A.M and such as single objects instead of all just part of 1 building that can't be changed, ability to move stuff you use in hub to other buildings(useful for multiple bases).
8. CCTV cameras with monitors, So you can watch your other factories from other locations, Incase one stops working for any reason (should be wired up to the CCTV hub, maybe use the power poles as 4 power cables and 2 CCTV wires?)
8.5. Continuation to monitors, monitors which can show the stats of certain things like power usage, how filled a storage is etc.
9. Ability to add railings to the stairs (so people don't fall off of high staircases, but some people can keep the railings off if they wish to)