Just saw the short track skating on tv and they let you cut across the "infield" to pass as long as you get back on the track by the finish.
I don't see why this isn't allowed in track and field.
And after seeing Oliver Tassinari at the Heps last year I wonder if it already is allowed. It would make for exciting finishes to say the least. Runners dashing to pass on the infield but having to do it before the finish.