Consisting of two disconnected segments – one linking Bethpage & Syosset, and the other linking Syosset & Oyster Bay Cove, County Route 9 was originally a continuous north-south route between Broadway (NY 107) in Bethpage and West Main Street (CR E52) in Oyster Bay.

CR 9 is owned and maintained by the Nassau County Department of Public Works, and consists of Berry Hill Road, Jackson Avenue, and South Oyster Bay Road.County Route 9 is split into two segments.

[2][3][4][5] From there, it runs north along the edge of the former airport property, soon reaching an intersection with Hazel Street and Grumman Road West on the Bethpage–Hicksville Line.

[2][3][4] From there, it runs northeast, reaching the southern terminus of CR E39 (Jackson Avenue / Cold Spring Road) one block later.

[6][7] When originally designated, County Route 9 formed a continuous north-south route between NY 107 in Bethpage and West Main Street (CR E52) in the hamlet of Oyster Bay, via South Oyster Bay Road, Jackson Avenue, Berry Hill Road, and Lexington Avenue.

[12] It continues to serve as a major access highway for freight traffic heading to and from the redeveloped site, which contains a large industrial park.