Indiana Code Title 9. Motor Vehicles § 9-20-1-3

Sec. 3. (a) This subsection does not apply to any highway or street in the state highway system.  Except as provided in subsection (e), local authorities, with respect to highways under their jurisdiction, may by ordinance:

for a total period not to exceed ninety (90) days in any one (1) year, whenever any highway by reason of deterioration, rain, snow, or other climatic conditions will be seriously damaged or destroyed without the regulation of vehicles.

(b) A local authority adopting an ordinance under subsection (a) shall erect or cause to be erected and maintained signs specifying the terms of the ordinance at each end of that part of any highway affected by the ordinance and at intersecting highways.  The ordinance may not be enforced until the signs are erected and maintained.

(c) Except as provided in subsection (e), local authorities with respect to highways under their jurisdiction, except highways in the state highway system and state maintained routes through cities and towns, may by ordinance do the following:

The prohibitions and limitations must be designated by appropriate signs placed on the highways.

(d) The Indiana department of transportation has the same authority granted to local authorities in subsections (a) and (c) to determine by executive order and to impose restrictions as to weight, size, and use of vehicles operated upon a highway in the state highway system, including state maintained routes through cities and towns.  These restrictions may not be enforced until signs giving notice of the restrictions are erected upon the highway or part of the highway affected by the order.

(e) The commissioner of the Indiana department of transportation may designate an order adopted under subsection (d) as a rule and adopt the order as a rule under IC 4-22-2.

(f) A local authority may not, in an ordinance passed under subsection (a) or (c), prohibit the operation of buses that are not more than forty-five (45) feet in length on any segment of the primary system (as defined in IC 8-23-1-33) that was in existence on June 1, 1991.