I like the layout you have drawn up ( was this done in MS paint? ) .
Only issue I ever had with the straights ( assuming on the far end ) was depending on how high / low the driver stand was you could kind of lose site of the vehicle in relation to the barriers.
For the regionals out in connecticut they did something interesting by running the straight from one corner to the other corner across the middle, I don't believe it was the full length but it was at least 3/4's the length of the track as far as the straight goes, was pretty nice.
I like what you drew up however so don't get me wrong, I am just throwing that out there as an FYI depending on how high the drivers stand is.