Interstate 575 (unsigned SR 417) is the 31-mile long Phillip M. Landrum Memorial Highway, which serves the far northern suburbs of the Atlanta metropolitan area. It is cosigned with SR 5 throughout while the old alignment of SR 5 parallels as a local road, maintained by either the county or city through which it passes.
The freeway connects Interstate 75 at Marietta with Nelson via Woodstock, Canton and Holly Springs along the SR 5 corridor. West of Nelson, when Interstate 575 crosses the Cherokee/Pickens County line, the route transitions directly onto SR 515 (ARC Corridor A), an at-grade expressway. SR 5 extends north along side SR 515 as the Appalachian Developmental (APD) Highway / Zell Miller Mountain Parkway to Ellijay.
Northwest Corridor Express Lanes
The Northwest Corridor project underway between November 2013 and September 8, 2018 constructed 29.7 miles of two reversible toll lanes along both I-75 and I-575 north of the Perimeter Highway (I-285). The express lanes extend north along I-575 to the interchange (Exit 11) with Sixes Road. Costs were estimated at $834 million for the entire project.
The American Association of State Highway and Transportation Officials (AASHTO) approved the establishment of Interstate 575 on October 28, 1977. The freeway was constructed in phases between 1979 and 1987.1,2:
- Interstate 75 north to SR 92 (Exit 7) – construction began in April 1978, opened on October 16, 1980.
- SR 92 (Exit 7) north to SR 5 Business / Riverstone Parkway (Exit 20) – construction began in 1981, opened on March 29, 1985; this incorporated the two-lane SR 20 bypass of Canton between Exit 16A and 19 that was built in 1978.
- SR 5 Business / Riverstone Parkway (Exit 20) north to SR 372 / Howell Bridge Road, opened in 1987.
A diamond interchange constructed at Ridgewalk Parkway opened to traffic on November 29, 2012. The $17.1 million project was first conceptualized in 1976. Opening of the new exit coincided with development of the adjacent Outlet Shoppes at Atlanta on the east side of the freeway.3