Officially the road is designated as National Route 126. The road is built to an expressway standard and is classified as a road for motor vehicles only (自動車専用道路, Jidōsha Senyō Dōro) (motor vehicles must have a displacement of at least 125 cc).
The road consists of two distinct sections. The first section (Chiba-higashi Junction to Tōgane Interchange) was opened in 1979 and connects the prefectural capital Chiba with the city of Tōgane. It is 4 lanes for its entire length.
The second section (Tōgane Interchange to Matsuo-Yokoshiba Interchange) was opened in 1998[2] and is 2 lanes. This section is designed to become part of the future Ken-Ō Expressway. The expressway will extend south beyond Tōgane Interchange (expected to open in 2009-2010) and north beyond Matsuo-Yokoshiba Interchange (route is currently under assessment).[3]