The Ken-O Expressway , or Metropolitan Inter-City Expressway , is a partially completed ticket system toll expressway in Japan. It is owned and operated by the Central Nippon Expressway Company and East Nippon Expressway Company. In conjunction with the Tokyo Bay Aqua-Line and the Bayshore Route of the Shuto Expressway, the expressway will form a full outer ring road of Tokyo. It is signed as National Route 468 as well as C4 under the "2016 Proposal for Realization of Expressway Numbering."

The Tokyo Bay Aqua-Line , also known as the Trans-Tokyo Bay Expressway, is an expressway that is mainly made up of a bridge–tunnel combination across Tokyo Bay in Japan. It connects the city of Kawasaki in Kanagawa Prefecture with the city of Kisarazu in Chiba Prefecture, and forms part of National Route 409. With an overall length of 23.7 km, it includes a 4.4 km bridge and 9.6 km tunnel underneath the bay—the fourth-longest underwater tunnel in the world.