The ideal solution would be to have:
4 races at road courses
4 races at restrictor plate tracks
8 races at tracks a mile or shorter
10 races at tracks between a mile and a mile and a half
6 races at tracks over a mile and a half not restrictor plates
2 street course races
1 all star race (for points) in an elimination style race
Thats 35 races right there, and no track would have a second date, only one date for each track so they hit every market.
Of course thats my opinion of an ideal solution to all the scheduling, but this is Nascar, it will never happen.