324.724.  Alternate route used, when. — Irrespective of the route shown on the special permit, an alternate route will be followed:

  (1)  If directed by a peace officer;

  (2)  If directed by a uniformed officer assigned to a weighing station to follow a route to a weighing device; or

  (3)  If the specified route is officially detoured.  Should a detour be encountered, the driver shall check with the department of transportation prior to proceeding.