KMZ files of the North Carolina section of the S-Line rebuild alignment are available for download if anyone wants to check them out. Fair warning: not all the files will import into Google My Maps, so if you want to look you’ll have to use Google Earth desktop.
https://connect.ncdot.gov/resources/Rail-Division-Resources/Pages/Rail-RelatedMaps.aspx
Filename - P-5753 R2R NC Rail Design KMZs