is a national highway connecting

Tokyo Tokyo, officially the Tokyo Metropolis, is the capital of Japan, capital and List of cities in Japan, most populous city in Japan. With a population of over 14 million in the city proper in 2023, it is List of largest cities, one of the most ...

and Shiojiri,

Nagano prefecture is a Landlocked country, landlocked Prefectures of Japan, prefecture of Japan located in the Chūbu region of Honshu. Nagano Prefecture has a population of 2,007,682 () and has a geographic area of . Nagano Prefecture borders Niigata Prefecture ...

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

. Originating at Nihonbashi in Chūō, Tokyo, it passes through Shinjuku and four other wards, and then seven cities, including Hachiōji in Tokyo. It follows a westward route into

Kanagawa Prefecture is a Prefectures of Japan, prefecture of Japan located in the Kantō region of Honshu. Kanagawa Prefecture is the List of Japanese prefectures by population, second-most populous prefecture of Japan at 9,221,129 (1 April 2022) and third-dens ...

, passing through the city of Sagamihara and one town. Continuing into Yamanashi Prefecture, the highway passes through nine cities and towns, among them the prefectural capital of Kofu. In Nagano Prefecture, National Route 20 passes through five cities and towns before entering Shiojiri, where it terminates at the intersection of National Routes 19 and 153. The highway is 225.0 km long. National Route 20 is the successor to the Kōshū Kaidō, an

Edo period The , also known as the , is the period between 1600 or 1603 and 1868 in the history of Japan, when the country was under the rule of the Tokugawa shogunate and some 300 regional ''daimyo'', or feudal lords. Emerging from the chaos of the Sengok ...

highway connecting the shogunal capital of Edo and Kofu, then the principal city in Kai Province (or Kōshū, as it was also known). Parts of it still bear the old name. The highway's course passes the Sakurada Gate of the

Tokyo Imperial Palace is the main residence of the Emperor of Japan. It is a large park-like area located in the Chiyoda, Chiyoda, Tokyo, Chiyoda district of the Chiyoda, Tokyo, Chiyoda ward of Tokyo and contains several buildings including the where the Emperor h ...

. Shinjuku Station is on National Route 20. The marathon course of the Tokyo Olympics included parts of National Route 20.

History

*4 December 1952 - First Class National Highway 20 (from

to Shiojiri, Nagano) *1 April 1965 - General National Highway 20 (from

to Shiojiri, Nagano)

Overlapping sections

*From Nihonbashi to Chiyoda (Sakuradamon intersection): Route 1 *In Hachioji, from Yokamachi intersection to Hachimancho intersection: Route 16 *In Otsuki, from intersection to Otsuki-bashi east intersection: Route 139 *From Kai (Ryuo-rittai intersection) to Nirasaki (Funayama-bashi kita intersection): Route 52

Intersects with

**Routes 4 and 15; at the origin, in Nihonbashi (Route 4 overlaps with 6, 14 and 17) ** Route 1; from Nihonbashi to Chiyoda ** Route 246; at Chiyoda ** Chofu IC, Chuo Expressway at Chōfu ** Kunitachi-Fuchu IC, Chuo Expressway at Kunitachi ** Route 16; at Hachioji *

** Route 412 and Sagamiko-Higashi Exit, Chuo Expressway; at Sagamihara ** Sagamiko IC, Chuo Expressway at Sagamihara * Yamanashi Prefecture ** Route 139 and Otsuki IC, Chuo Expressway; at Otsuki ** Route 137; at Fuefuki **Routes 140 and 358; at Kofu ** Route 52; from Kai to Nirasaki ** Route 141; at Nirasaki *

Nagano Prefecture is a Landlocked country, landlocked Prefectures of Japan, prefecture of Japan located in the Chūbu region of Honshu. Nagano Prefecture has a population of 2,007,682 () and has a geographic area of . Nagano Prefecture borders Niigata Prefecture ...

**Routes 152 and 299; at Chino ** Route 142; at Shimosuwa **Routes 19 and 153; at the terminus, in Shiojiri

References

{{National Routes of Japan, 20 020 Roads in Kanagawa Prefecture Roads in Nagano Prefecture Roads in Tokyo Roads in Yamanashi Prefecture 1952 establishments in Japan