My local hobbyshop has had two tracks: approximately 66 x 48 and 90 x 42. There's nothing like the bigger track, but what you need to look at is the environment the track is going to be in. What ever size track you build just make sure you can keep traction in it. That will attract all levels of racers. And racers are what you want. The ideal track would be 100 x 50 with traction so your layouts are limitless. I am happy just being able to race, so I have no choice. I am greatful. Good luck