My son (3 yrs old) is very fond of trains, and we often build elaborate tracks using the Brio style tracks and accessories.

I've seen/heard of Railroad Tycoon, and just now found online discussions of A-Train, a Mac & Amiga game from the early 90's.

I'm interested in finding a simple 'Railraod Construction Set' sort of software; if the software has detailed graphics showing trains travelling the tracks that's even better.

Would either of the above fit the bill? Do you guys have any recommendations? There doesn't really need to be any gameplay - that's not what I'm after. I just want us to be able to design different tracks and watch trains travel on them.

I tried checking out the RRTycoon 3 site to see if it had any sort of eval download, but the site is absolutely terrible - clogged with so much Macromedia I gave up before finding any useful info. It took ages to actually display anythign on my DSL/P4-2.4 laptop.