Interstate 65 (I-65) is part of the Interstate Highway System that runs 887.30 miles (1,427.97 km) north–south from Mobile, Alabama, to Gary, Indiana. In Tennessee, I-65 traverses the middle portion of the state, running from Ardmore at the Alabama border to the Kentucky border near Portland. The route serves the state capital and largest city of Nashville, along with many of its suburbs. Outside of urban areas, the Interstate bypasses most cities and towns that it serves, instead providing access via state and U.S. Highways. The Interstate passes through the Highland Rim and Nashville Basin physiographic regions of Tennessee, and is often used as the dividing line between the eastern and western portions of the former.

A high-occupancy vehicle lane is a restricted traffic lane reserved for the exclusive use of vehicles with a driver and at least one passenger, including carpools, vanpools, and transit buses. These restrictions may be only imposed during peak travel times or may apply at all times. There are different types of lanes: temporary or permanent lanes with concrete barriers, two-directional or reversible lanes, and exclusive, concurrent, or contraflow lanes working in peak periods.