Sec. 9. (a) Except as provided in subsections (b) and (c), all rules of statewide application shall be adopted under IC 4-22-2.
(b) Traffic regulations carrying a penalty for violation and requiring the use of signs or markers to make them effective need not be adopted under IC 4-22-2.
(c) Traffic regulations, except maximum speed limits and worksite speed limits, shall be officially adopted by order of the Indiana department of transportation.