This polyline datalayer depicts major road routes and associated attribute data for the Atlanta Regional Commission's (ARC) 10-county region. ARC documentation states that: The features included in this Theme were identified by ARC's Transportation Planning Division (TPD) as major roads. Although this Theme may not include roads considered major for all purposes, it is a useful network of regionally significant routes in the Atlanta Region. This Theme is a subset of ARCmap, ARC's street centerline database. Please note that ARCmap has recently been combined with the Georgia Department of Transportation (GDOT) DLGF street base and the 2000 Census TIGER street centerline file to create the State's new Addressed DLGF database.