To answer your question, hit edit, select all, and then hold control a de-select the parts of the lift hill you want to have catwalks. While everything is still selected, double click a piece of track, go to auto-supports, and check off "individual settings" ONLY! Nothing else. Then go back and highlight Just lift hill, double click, auto-supports, check off individual settings and left/right catwalks. Voi La, you're done.
Then just go to the auto support generator and it will work from there.