 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.For instance, Spur 208 into Liberty was renumbered S-34A and Spur 715 into Western was renumbered S-76C.