Indiana Code Title 9. Motor Vehicles § 9-21-8-20

Sec. 20. The Indiana department of transportation may by resolution or order entered in its minutes, and local authorities may by ordinance, with respect to any freeway or interstate highway system under their respective jurisdictions, prohibit the use of a highway by pedestrians, bicycles, or other nonmotorized traffic or by a person operating a motor driven cycle. The Indiana department of transportation or the local authority adopting a prohibiting regulation shall erect and maintain official signs on the freeway or interstate highway system on which the regulations are applicable. If signs are erected, a person may not disobey the restrictions stated on the signs.