The road is designated as a spur of SR 15, and was formerly numbered State Road 15A. It has also been – and may still be – an unsigned U.S. Route 17 Alternate (US 17 Alt.), which originally continued east on I-10 and north on I-95 to return to US 17 north of the Trout River. Roosevelt Expressway is the bypass built as a spur of I-10, which converted US 17 into a limited-access Expressway north of Blanding Boulevard (SR 21), bypassing the Post Street/College Street route that Roosevelt Boulevard used to travel through the Riverside and Avondale historic district, passing by McDuff Avenue (SR 129) to I-10 eastbound. The expressway is accessible southbound via I-10 west as a left exit (exit 361). The current design was preferred over the proposed River Oaks Freeway, which would have decimated the Avondale district. The partial interchanges with Blanding and I-10 reflect the nature of the original need of a bypass system. Intended to stimulate commerce and encourage connectivity to Jacksonville's downtown to and from the suburbs and Orange Park, while streamlining commutes and lessening the impact such travel was to potentially have on Jacksonville's oldest areas in the southwest side of town by removing high volume and chaotic redevelopment from the streets of Avondale and Lakeside Park, the area east of the Roosevelt Expressway is now protected in the form of a zoning overlay largely allowed by the basic design of this alternate route. Roosevelt Expressway has been signed in the last number of years as Roosevelt Boulevard, even though it's still in the JTA books as Expressway. It is part of the Blue Star Memorial Highway, and named for President Franklin D. Roosevelt. In early 2006, the Florida Department of Transportation applied to the American Association of State Highway and Transportation Officials to reroute US 17 via the Roosevelt Expressway, I-10, I-95 and US 23. If this is accepted, US 17 Alt. will be eliminated. As of March 2007, it appears that US 17 has been rerouted. US 17 goes north on the Roosevelt Expressway, to east I-10 (SR 8), north on I-95, and east on Union Street (US 23) until Main Street and picking back up on its original course. U.S. Route 17 Alternate (US 17 Alt.) was an alternate route of US 17 that existed entirely within the city limits of Savannah.