At the Hardeman County Courthouse, SR 18 breaks away from US 64 and turns left on North Main Street.

Outside the Bolivar city limits, SR 18/SR 125 continue north through the Hatchie River bottoms before reaching the community of Shandy.

SR 18 continues as a two-lane route through rural southwestern Madison County and passes through the community of Medon and Malesus just south of the Jackson city limits.

In Jackson, the route ends at an expansive signalized intersection with US 45 and hidden SR 5, known locally as South Highland Avenue.

[6] This work is part of a larger effort by TDOT to widen SR 18 from Bolivar north to Jackson as directed in House Joint Resolution 16 of the 98th Tennessee General Assembly.