I wou;d go with 2 lanes. Its the in-fighting, timeing of re-fueling and strategic decisions that make digital diffrent. Big track and there is nobody to interact with after a lap or two. Personally on something that size you could get to 8 cars before it felt too busy I recon. Remember 6 cars is the SSD limit. Having read a bit I recon its either SSD or the expensive stuff Scorpious or Oxygen. The latter two may be better as although I love SSD on a large track you may need powerful cars. SSD has a chip limit of about 18k motors without changeing the chip. Unless you do it yourself the chips are not that cheap and so systems with larger capacities might be better. If its a 150 foot of hell (YES!) with no long boring straights then SSD might be an option.