I'm not sure about the state, but I think there is a city ordinance about single-file for Lincoln.
I'm just super happy about having a practical and rational interpretation of "as close to the right as practicable" in some form of print! That seems to be a real sticking point around here, and it would be great if drivers were able to see that cyclists aren't trying to be jerks when they "take the lane." This certainly has the potential to help out.