thanks for the answers. i'll get down to modding the map then?... hopefully i'll figure it out myself relatively fast. if not, i'll just browse the modding part of the forum.
but z positions? so that means that all the trouble of calculating coordinates and lane lengths was in vain? 
oh well, as close to a perfectly balanced map as i'll ever get
(since i presume that the z position is not editable), so we'll just have to get by with what we have.
oh, and yes, the map was created for me and two friends. we plan to have a week long LAN party and settle some outstanding accounts 