The original 'highway' from Durham to Chapel Hill (and vice-versa.) In town, the road became/becomes Chapel Hill Street. With the construction of Chapel HIll Boulevard in the early 1950s, Chapel Hill Road became known as "Old Chapel Hill Road" south and west of University Drive (which also cut a more direct path east-west.) I don't make that distinction on this site. There are a few articles about the dangerous nature of Chapel Hill Road in the mid-20th century accounts. I believe Wyatt Dixon called it "that old black snake."
There is at least one source that names the road as the "Jefferson Davis" highway. I've never seen this elsewhere, and I'm not familiar with it as a common usage.