I think the exit might be a bit too long - Perhaps we should just limit it to the thick not-entirely-white/beige-ish line for especially the exit.
I also think having those markers all the way around the track is unnecessary and potentially gives the gfx board more to chew on. I at least don't see any need for them, and they also could get in the way, if you are a tad too much on the edge, but not on the grass.
Just my 2 cents.
Ps. I don't mind the amount of marker along the lines - the amount seems to do the job quiet well.
Edit: Hm.. I'm using hires textures, so the thick line I'm reffering to may not look the same on yours - I'll do a screenie.