Very well, Martin, nixt the idea. I should worry more about my trains functioning satisfactorily. I once rode on the Amtrak California Zephyr and did see cars moving on highways out the window. Real railroads do operate in the real world with non-railway-related things going on around them. For example, I wish my Microsoft flight simulator, though it features working road vehicles, surface boats and ships, would furnish moving trains, people, animals and railroads as scenery on the ground below the flying planes and helicopters to make it more interesting.
I've heard it talked about before, but someday, we will have a PC/console World Simulator, with all kinds of interactive vehicles, machinery and animals to virtually jump into, mount, get in, get on, and drive, ride, operate, fly, cruise or sail all in the SAME game. This could be the kind of grand simulator game that the likes of N3V is cooking up behind closed doors over the next five years.
Imagine the following all human drivable and/or AI drivable/programmable within the same sim:
-space ships
-farm tractors
-earth movers
-army tanks
-submarines
-speed boats
-trains
-planes
-hand cars
-oil tankers
-cruise ships
-camels
-roller skates
-snowmobiles
-horses
-ox carts
-wagons
-mules
-cars
-motorcycles
-semi trucks