[2] Along with the Ken-Ō Expressway, Route 16 connects the entire length of the Technology Advanced Metropolitan Area (TAMA) Network region - an inland industrial area covering an area of 3000 km2, covering 74 municipalities and home to over 10 million people of whom 4 million work in the TAMA Network firms.

In 1998 goods shipped from TAMA had twice the shipment value of the Silicon Valley.

[3] Before 1963, the route did not follow a loop, but ran from Futtsu to Yokosuka to Yokohama.

The Yokosuka-Yokohama section was designated as National Highway 45 on 8 July 1887 and became National Highway 31 in 1920 and Route 16 in 1952.

This article relating to the roads and highways in Japan is a stub.