|Good background definition on County Roads: https://en.wikipedia.org/wiki/Numbered_roads_in_Indiana#County_Roads_in_Indiana|
See Indiana/Special roads for guidance in Indiana that may not be universal to all other states and territories.
Roundabout Speed Limits
Indiana deviates from the GLR/National standard here. The Indiana policy is to set the speed limit to the lowest speed limit among the feeder roads for the roundabout