I have taken half an hour off to play with a simulation package.
I downloaded the 22MB file b389r4den.exe and installed it.
I have not explored it fully but am fascinated by an animated trench digger and a diversion route - the streetcars are running around the earthworks in this screen snapshot:-
- Untitled.png (24.15 KiB) Viewed 761 times
Cheers
Chris