Morning he who isnt really the walrus. I'm pretty new to this but have some comments that I hope will benefit you in your build. Like many on here, it all started when I got a Scalextric loop track for Xmas when I was about five. It had vintage F1 cars with little pin at the front that you could pull out to get 'real' car engine noise. That track got added to and modified for several years until I discovered other wonders of the world such as homework and females. Anyway, couple of years ago, I discovered this forum and realised some other adults still craved to play slotcars!! Having a young girl meant I had the perfect excuse to spend a little bit of money and put a track together..... family time
I tried a plastic offering to start with but it didnt really do what I wanted and there was alot of talk on here around routing a track so I decided to give that a go.
As the others like Munter have mentioned, I think the first stage will always be draw 50 tracks on paper and try to see what you want in a design. I did this and eventually, ended up pinning my favourite one on the wall and now have something with cars running on it that resembles the sketch quite closely.
Number of lanes is a major as it is so related to the amount of space you have, the type or size of table you want and the number of friends called Marshal you can round up. I saw my track as a father-daughter project and wanted as much driving lane in small space as I could get plus I have no mates called Marshal so I opted for only two lanes. In hindsight, I would probably go with at least three next time.
The style of track can also be a difficult decision. I like all sorts of car styles and motor sport so I struggled with how to do this. Rally cars mixed with racing trucks and F1??? Dawned on me at some stage that I could do what I consider a targa/hillclimb style track and thereby realistically run all sorts of vehicle in a sort of "Historic Day" type race scenario. This might not be important to you but allowed me to have a track with elevation, lots of different turns, squeezed lanes and a long back straight, etc.
What I hope might be helpful to you are the things I got 'wrong':
I didnt worry at all about the length of each lane. I'm not aiming at team or club racing so I figure that the levels of driving, differences between cars, marshalling lack of skill and other variables will all even things out. If it was an issue, we could race x number of laps on lane 1 then swap and race x laps on the other lane or something.
I used copper tape to save money - I wish I had paid the extra for braid.
I didnt allow enough room on the outside of my corners. In my old Scalextric days, it was normal for the cars on outside lane to fly around the corners with the tail dragging along the barriers. I left a normal lane width on outside of my lanes and now my prized NSR and Pioneer cars drag their butts around my simulated concrete walls which is horrible. I'm now faced with trying to add a border style strip around some of my corners to widen the lanes so the cars need to drive around the turn. Rather hard to do - make sure there is room when you are planning and building!!
Last but not least - dont underestimate how much you will love the track and how much you will spend on cars you just have to have!!!!!!
Hope what I have added here will benefit you in your build. Look forward to seeing what you ddecide on and how it goes.