It connects the cities of Tanabe and Kinokawa, spanning the western side of the prefecture in a south–north routing.

The highway almost entirely runs through the prefecture's inland mountainous area, paralleling the coastal routing of National Route 42 and the Hanwa Expressway; however, the southernmost section of the highway between Minabe and Tanabe runs along the prefecture's west coast.

[4] In 1996 a project began to widen and straighten a winding one-lane section of the road along the Shuri River in Aridagawa.

The project was significantly delayed by landslides caused by Tropical Storm Talas on 5 September 2011.

[5] On 2 October 2017, the project was completed, shortening the total length of the highway by about a kilometer and a half.