Prior to the 1970s, short spur routes that were offshoots of main highways were given route numbers based on the main highway.

The spurs were numbered sequentially from west to east or north to south and prefixed to the main route's number.

In 1970, the Nebraska Department of Roads gave all of the state spurs new route numbers.

The change was initiated to create a system of secondary highways that was expandable and followed a pattern.

The new route numbers were given a letter prefix of S, L, or R, for Spur, Link, or Recreation Road, respectively, a number which identified the county in alphabetical order, and a letter suffix identified each particular route.