Indiana Code Title 8. Utilities and Transportation § 8-8-10-1

Sec. 1. Every railroad operating wholly or partly in Indiana must place and maintain a signal light or a reflectorized switch target upon each switch and each derail switch which is connected with the main track of the railroad.  The signal light or the reflectorized switch target must indicate the position of the switch and be clearly visible at all times.  Every switch position indicator must indicate safety when the switch is set to the main track and must indicate danger when the switch is not set to the main track.