Indiana Code Title 9. Motor Vehicles § 9-21-4-12

Sec. 12. (a) The Indiana department of transportation may determine by an engineering and traffic investigation those parts of a state highway where overtaking and passing or driving to the left of the roadway would be especially hazardous and may, by appropriate signs or marks on the roadway, indicate the beginning and end of the zones.

(b) The Indiana department of transportation may determine that a bridge, a culvert, or an approach to a bridge or culvert on a state highway does not have sufficient clear roadway width to safely permit the passing of two (2) vehicles. A bridge or culvert described in this subsection shall be designated a one-lane bridge or a narrow bridge.