National Route 1 (Japan)

National Route 1 (Japan)
Country	Japan
Type	National
Length km	565.1
Established	1952
From	Tokyo
To	Osaka
Major cities	Yokohama, Shizuoka, Nagoya, Kobe

National Route 1 (Japan) is a principal arterial highway linking Tokyo and Osaka across the island of Honshū. The route connects major ports, industrial centers and historic cities such as Yokohama, Shizuoka, and Nagoya while paralleling rail corridors like the Tōkaidō Shinkansen and the Tōkaidō Main Line. It forms part of Japan's numbered national highway system created in the early postwar era and traces sections of the historic Tōkaidō road.

Route description

The highway begins in central Tokyo near the Nihonbashi area and proceeds southwest through the Tokyo Bay coastal plain into Kanagawa Prefecture passing through Yokohama, Kawasaki, and Yokosuka suburbs before turning west toward Shizuoka Prefecture. In Shizuoka Prefecture it passes through Fujinomiya, skirts the foothills of Mount Fuji, and follows the Pacific coast through Numazu and Atami before entering Aichi Prefecture and the Nagoya metropolitan region near the Nagoya Port. Westward from Nagoya the route continues through Gifu Prefecture outskirts into Mie Prefecture and then through Osaka Prefecture suburbs to terminate in Kita-ku, Osaka. Along its length the highway intersects major expressways including the Shuto Expressway, the Tōmei Expressway, the Meishin Expressway, and the Hanshin Expressway network, and runs adjacent to railways such as the Tōkaidō Shinkansen, the JR Central Tōkaidō Main Line, and private lines like the Keihin Electric Express Railway.

History

The corridor follows the path of the Edo-period Tōkaidō route linking Edo and Kyoto, used by daimyō on sankin-kōtai processions and pilgrims visiting Ise Grand Shrine. During the Meiji era modern roads and railways were established along the same corridor connecting Tokyo Station and Osaka Station nodes. In the 20th century national road planning by agencies including the Ministry of Transport and successor ministries formalized the numbered system in 1952, designating this corridor as Route 1. Postwar reconstruction and industrial expansion in Keihin, Chukyo, and Hanshin regions drove upgrades, while events like the 1964 Summer Olympics in Tokyo and the Expo '70 in Osaka spurred infrastructure investment. Natural disasters such as the Great Hanshin earthquake influenced seismic retrofitting and alignment changes in the late 20th century.

Major junctions and interchanges

Key urban junctions include connections with the Shuto Expressway at Nihonbashi and Yaesu in Tokyo, interchange links to the Tōmei Expressway near Yokohama, and the Isewangan Expressway and Meishin Expressway interchanges in the Nagoya area near Kiyosu and Komaki. West of Nagoya the route meets expressways serving Gifu, Nara, and Kobe including junctions with the Chūgoku Expressway corridors and the Hanshin Expressway approaches to Osaka Bay facilities. Important local nodes connect to ports such as Yokohama Port, Nagoya Port, and Kobe Port, and to airports including Haneda Airport and Kansai International Airport via feeder routes.

Traffic and usage

Route 1 carries heavy commuter traffic in the Greater Tokyo and Nagoya metropolitan areas, with substantial freight movements between industrial zones like the Keihin Industrial Zone and the Chūkyō Industrial Area. Peak-hour congestion frequently affects stretches through Yokohama and central Nagoya where commuters transfer to rail hubs such as Yokohama Station and Nagoya Station. Commercial trucking links manufacturing centers in Aichi Prefecture and distribution centers serving retailers like Aeon and Seven & I Holdings; passenger services include long-distance buses connecting Tokyo Station and Osaka Station with stops at highway bus terminals. Seasonal tourism traffic increases access to destinations including Hakone, Mount Fuji, and Ise Grand Shrine.

Road infrastructure and developments

Upgrades over decades have included widening to multi-lane urban arterials, grade separations, seismic strengthening, and installation of intelligent transport systems (ITS) overseen by bodies such as the Ministry of Land, Infrastructure, Transport and Tourism. Urban sections incorporate elevated viaducts and bypasses to alleviate congestion in historic city centers like Odawara and Kobe. Projects have coordinated with rail expansions by operators including JR East, JR Central, and JR West and with port modernization at Yokohama Port and Nagoya Port. Recent initiatives address disaster resilience after events like the 2011 Tōhoku earthquake and tsunami and technological adoption includes traffic monitoring using systems developed with participation from corporations such as Nippon Telegraph and Telephone and Panasonic.

Cultural and economic significance

The route parallels the historic Tōkaidō cultural corridor featured in works by artists like Utagawa Hiroshige and in literature about travel between Edo and Kyoto. Cities along the highway host cultural institutions such as the Tokyo National Museum, the Nagoya Castle, and the Osaka Castle, and festivals like Gion Matsuri and Tenjin Matsuri draw visitors using Route 1. Economically, the highway underpins manufacturing clusters in Aichi Prefecture (notably companies such as Toyota Motor Corporation), port logistics at Nagoya Port and Kobe Port, and retail distribution supporting conglomerates including Rakuten and Mitsubishi Estate. The corridor remains a backbone of intercity connectivity influencing regional planning by entities such as Tokyo Metropolitan Government and prefectural governments in Kanagawa Prefecture, Shizuoka Prefecture, and Osaka Prefecture.

Category:Roads in Japan Category:National highways in Japan