[3][4] The route serves as both a bypass around downtown Franklin and as a major thoroughfare for traffic traveling between residential and commercial areas within the city.

[5] SR 397 begins at an intersection with US 31 (Columbia Pike) south of downtown Franklin in an eastward alignment, where it also carries the US 31 Truck designation.

The highway then crosses the Harpeth River before turning north and passing through a wooded area before widening to four lanes and reaching an intersection with SR 96 (Murfreesboro Road).

Passing a golf course and wooded area, the parkway crosses Spencer Creek and the CSX railroad for a second time, before once again intersecting with US 31 (Franklin Road), where US 31 Truck ends.

Entering the outskirts of Franklin, the route continues westward, reducing to two lanes and crossing the Harpeth River for a third and fourth time in short succession on a single long bridge.

[7] The central business district had begun to suffer from congestion due to the multiple highway spokes which intersect there and the lack of outer connections between them.

[9][10] An environmental impact statement for the project was approved by the Federal Highway Administration (FHWA) on July 31, 1981, which was referred to at the time as the Franklin Bypass.

[19] On December 2, 2005, TDOT announced that the preferred alignment for the Mack Hatcher Parkway Western Extension would be Alternate G, which is the shortest of the considered routes at 7.51 miles (12.09 km) long.

[18] This decision was subject to much criticism from local residents, and throughout the 2010s, many political candidates in Williamson County utilized the project as a campaign tactic.

[24] A dedication ceremony for the section occurred on December 13, 2021, which included the naming of the Harpeth River bridge in memory of former state representative Charles Sargent.