CTR splits dofs

[ammods]

i'm doing some track making, and when i export a single file, it splits the dofs up, is there any possible way we can prevent this from happening. as i need to get my dof count down, but i cant if it keeps splitting the dofs..last time i tried this with the track i'm working on, i ended up with around 7000 dofs, this isnt acceptable because it knocked my frame rate on its arse...

help please.