Interstate 475 (I-475) is a 15.83-mile-long (25.48 km) auxiliary Interstate highway in Georgia, splitting off from I-75 and bypassingMacon. It is also unsignedState Route 408 (SR 408). This is the preferred route for through traffic, as I-75 enters downtown Macon and reduces to four lanes (two in either direction; undergoing widening), and has a 60-mile-per-hour (97 km/h) speed limit, in addition to the highway interchange with I-16.
I-75 northbound sign at Hartley Bridge Road for I-475 north in Macon
I-475 carries six lanes (three in each direction) throughout its entire route (expanding to eight lanes at both junctions with I-75), except at its northernmost terminus with I-75, where it briefly reduces to four lanes.
Built in stages between 1965 and 1967, I-475 was originally built with two lanes in each direction, and a wide median with forest, mostly of sweetgum trees. When the one lane was added in each direction, every bit of the median was paved, with a full-lane-wide shoulder in both directions instead of the normal very narrow ones, and a Jersey barrier, rather than leaving or replanting any trees or other landscaping or native vegetation.
In 1965, the entire length of the highway was under construction. The next year, the entire highway was open.
The Bibb County Commission named the highway in honor of former Commission Chairman Larry Justice, who retired in 2000.