Inspired by 3D I'm in the process of constructing my own take on a diecast downhill track and while I've achieved some interesting layouts through experimentation I was wondering whether there's any theoretical work that can be done. After all, if I can spend 20 mins theory-crafting a layout it's way more efficient than tinkering over 3 or 4 hours (albeit not as much fun). So, here are a few questions: - Is there an optimum angle of descent? - I notice 3D employs segregated lanes before merging later on, what's the rationale here? - How much testing do you do before committing to a layout? - What are the criteria for a successful test? For those interested, I'm building out of wood using prefabricated banked corners, overlaying the whole thing with carpet protector to smooth out joins, create moguls and so on. I'll share pics when I'm a little further along.