Long SR's are connecting roads, funneling rural traffic to and between primary highways and smaller villages. Short SRs provide access to residences. Long SRs are usually paved. Although they are generally designed for slightly lower travel speeds than highways are, many long SRs are still suitable for travel at 50-55 mph. They usually carry only a few hundred vehicles per day, whereas most rural highways carry well into the thousands per day.
Short SRs tend to be unpaved and lack most modern design features.
They typically carry fewer than 100 vehicles per day, almost all of which are local residents. Locals usually use the names without any idea what the numbers are, but numbers may be easier to find on maps. SRs are renamed more often than they are renumbered, so maps that use names instead of numbers can get out of date. N.C. Sometimes a road has more than one colloquial name, and often an SR is most easily identified by the state highway that used to run along it. A good example is the road that runs along Linville Mountain in Burke County, which I've seen denoted as Old N.C. 105, Kistler Memorial Highway, County Line Road and SR 1238.