Inner Circular Route (C1)

A 14.8-kilometre loop of elevated expressway encircling central Tokyo, opened in stages from December 1962 to 1967. The backbone of the Shuto Expressway network, C1 threads above rivers, moats, and filled canal beds through the heart of the city.

A Loop of Steel Above the City Core

Walk through central Tokyo and you will quickly notice the elevated expressway overhead. The most prominent of these structures is the Shuto Expressway Inner Circular Route — signed as C1, colloquially called tōkan — a loop of approximately 14.8 kilometres that encircles the Imperial Palace and threads through the three central wards of Chiyoda, Chuo, and Minato.

The first section opened in December 1962, linking Kyobashi to Hamasaki Bridge Junction over a stretch of about 2.7 kilometres. Construction proceeded under what engineers nicknamed the “aerial offensive,” an extraordinary pace driven by the approach of the 1964 Tokyo Olympics. Work continued beyond the Games, and by 1967 the loop was closed. Since then, C1 has served as the hub from which radial routes branch outward: Route 1 to Ueno, Route 2 to Meguro, Route 3 to Shibuya, Route 4 to Shinjuku, Route 6 to Mukojima, and several others.

Elevated, Sunken, Tunnelled

What makes C1 structurally distinctive is its variety. The route alternates between three modes: elevated sections that span rivers and moats; sunken sections running through the filled-in beds of former canals such as the Kaede and Tsukiji rivers; and short tunnel sections cutting through hillsides. Almost none of the route runs at grade.

Building above existing waterways was a deliberate solution to a difficult problem — threading a motorway through the densest urban fabric on Earth while minimising the demolition of existing streets. The tradeoff was a structure that, in the case of Nihonbashi, came to hang directly above a historic stone bridge, covering it from the sky. That intrusion has been debated for decades; a project to relocate the Nihonbashi section underground is currently under way.

The elevated deck along the Ginza and Kasumigaseki corridors — glassy office towers rising on either side, the expressway cutting between them at mid-height — is among the more photogenic passages of postwar urban infrastructure anywhere in Tokyo. It is a reminder that Showa-era engineering remains actively in service beneath the city’s contemporary surface.

Summary

The Shuto Expressway Inner Circular Route (C1) is a 14.8-kilometre loop opened in stages between December 1962 and 1967. Encircling the core of Chiyoda, Chuo, and Minato wards, it functions as the central node of the entire Shuto network. Its alternating elevated, sunken, and tunnel sections reflect the ingenuity — and constraints — of 1960s urban infrastructure planning in a city that could not stop to be rebuilt.

You do not need to drive C1 to experience it. Walking the streets of Ginza or Kasumigaseki, the expressway is close overhead; its concrete and steel have become as much a part of the visual grammar of central Tokyo as any building beneath it.

Related: Tokyo International Forum / JP Tower (KITTE)

Staying in central Tokyo near the C1 corridor? Rakuten Travel offers a wide selection of hotels in the area.