Indiana Code Title 9. Motor Vehicles § 9-21-5-10

Sec. 10. (a) A person may not drive a vehicle over a bridge or other elevated structure constituting a part of a highway at a speed that is greater than the maximum speed that can be maintained with safety to the bridge or structure, when the structure is signposted as provided in this section.

(b) The Indiana department of transportation may conduct an investigation of a bridge or other elevated structure constituting a part of a highway. If the Indiana department of transportation finds that the structure cannot with safety to the structure withstand vehicles traveling at the speed otherwise permissible under this chapter, the Indiana department of transportation shall determine and declare the maximum speed of vehicles that the structure can withstand. The Indiana department of transportation shall cause or permit suitable signs stating the maximum speed to be erected and maintained at a distance of one hundred (100) feet or as near as practicable before each end of the structure.

(c) Upon the trial of a person charged with a violation of this section, proof of the determination of the maximum speed by the Indiana department of transportation and the existence of signs erected under subsection (b) constitutes conclusive evidence of the maximum speed that can be maintained with safety to the bridge or structure.

(d) A person who exceeds the speed limit sign posted on a bridge or other elevated structure under this section commits a Class C infraction.