Chuo Shinkansen

The project is the culmination of Japanese maglev development pursued since the 1970s. After the Tōkaidō Shinkansen opened between Tokyo and Osaka in 1964, Japanese National Railways (JNR) turned to developing faster maglev technology, starting work in 1972, and in the 1970s built a 7 km test track for maglev research in Miyazaki Prefecture. Once the desired results had been obtained there, construction of a test track in Yamanashi Prefecture between Ōtsuki and Tsuru began in November 1990; to save costs, only an 18.4 km initial section of the planned 42.8 km, incorporating tunnels, bridges and slopes, was built at first, and running tests began on 3 April 1997. An unmanned run reached 550 km/h there on 24 December 1997, and trains on the Yamanashi test track routinely achieved operating speeds of over 500 km/h. The track was later extended a further 25 km along the future route of the Chūō Shinkansen to bring its combined length to 42.8 km, with the extension and upgrade work completed in 2013; testing with the L0 Series service-type trains on the full line began on 29 August 2013. JR Central now operates the facilities and research, and the Chūō Shinkansen is intended to extend and incorporate the existing Yamanashi test track.

A maglev 'Second Tōkaidō Shinkansen' had originally been envisaged, but the idea was merged with the Chūō Shinkansen plan, and so the Chūō Shinkansen is being built as a maglev line. On 15 November 1973 the line was designated a basic-plan route under the Nationwide Shinkansen Railway Development Act, after which topographical and geological surveys were carried out, including on the mountain tunnel sections between the Kōfu and Nagoya areas. The long closure of the Tōkaidō and Sanyō Shinkansen after the Great Hanshin earthquake was cited as showing the need for an alternative (bypass) route to the Tōkaidō Shinkansen, which crosses the area expected to be hit by a Tōkai earthquake; the ageing of the Tōkaidō Shinkansen itself was another reason given for building the line. In 2008 JR Central decided to build the line on the direct route, Plan C.

The development plan for the line was decided on 26 May 2011. Government permission to proceed with construction was granted on 27 May 2011, when the Ministry of Land, Infrastructure, Transport and Tourism instructed JR Central — already named as the line's construction and operating entity — to build the line. JR Central had announced in December 2007 that it would fund construction of the section between the Tokyo area and the Chūbu region on its own, without government financing, at an estimated total cost of about 5.1 trillion yen; the May 2011 development plan put the construction cost of the whole Tokyo–Osaka line at over 9 trillion yen. The Ministry approved Plan C for construction of the Shinagawa–Nagoya section on 17 October 2014, and construction began on 17 December 2014. Construction of a 25 km tunnel under the southern Japanese Alps commenced on 20 December 2015, reaching roughly 1,400 m below the surface at its deepest point; upon completion it is expected to surpass the 1,300 m-deep Daishimizu Tunnel on the Jōetsu Shinkansen as the deepest tunnel in Japan. The line's high expense is driven largely by the fact that most of it runs underground — about 86% of the initial Tokyo–Nagoya section — with some sections built as deep underground at a depth of 40 m.

The line's opening target has slipped repeatedly, largely because of a dispute with Shizuoka Prefecture, the only prefecture along the Tokyo–Nagoya route to receive no new station. The prefecture expressed concern that water from the Ōi River would leak into the tunnel and lower the river's water level, and in a June 2020 meeting Shizuoka officials denied permission to begin tunnel construction. JR Central announced the following week that opening the Tokyo–Nagoya line in 2027 as previously planned would be 'difficult'. In December 2023 it applied to the Ministry to change the planned opening from 2027 to '2027 or later', and in March 2024 it abandoned the 2027 target. Less than a week later, on 2 April 2024, Governor Heita Kawakatsu, re-elected in June 2021 partly on a platform of continued opposition, announced that he would resign. The ensuing by-election on 26 May 2024 was won by Yasutomo Suzuki, described as a maglev proponent, after which preliminary work was approved and proceeded. In January 2026 Suzuki and JR Central President Niwa signed a letter of agreement under which JR Central would compensate for any decrease in Ōi River water resources without requiring the prefecture to prove the construction caused it, and on 26 March 2026 a Shizuoka special committee approved all 28 environmental conservation measures proposed by JR Central. JR Central said in 2024 that the Tokyo–Nagoya line was not expected to open until at least 2034; in 2025 the outlook was reported to have slipped to no earlier than 2035.

The Nagoya–Osaka extension was originally planned to open as late as 2045, a schedule designed to keep JR Central's total debt below its level at the time of privatisation; after the company received a loan from the Japanese government the completion date was brought forward to as early as 2037. The Osaka prefectural government and Kansai-region businesses had raised concerns about the impact of the delayed extension on the Osaka economy, and Kansai politicians called for and received state-backed loans to expedite the line, moving the extension's opening forward by up to eight years.

The Chūō Shinkansen will employ the SCMaglev system developed by JR Central, in which the levitating force is generated between superconducting magnets on the trains and coils on the track; the superconducting coils use a niobium–titanium alloy cooled with liquid helium. The absence of wheel friction allows higher speeds and greater acceleration than conventional high-speed rail. Its rolling stock is the L0 Series. The earlier MLX01 was tested on the initial section of the Yamanashi test track until 2011; on 2 December 2003 a three-car MLX01 set a manned world record of 581 km/h there, certified by Guinness World Records the following year. On 26 October 2010 JR Central announced the L0 Series for commercial operation at 505 km/h, and it went on to set a manned world record of 603 km/h on 21 April 2015. On 26 March 2020 the Improved L0 Series began operations on the test track — the first to draw power from the track rather than from on-board gas generators.

• 1962A target of one hour between Tokyo and Osaka (about 500 km) is set, and attention turns to frictionless superconducting levitation.
• 197315 November: the Tokyo-Osaka corridor is designated a basic-plan Shinkansen route under the Nationwide Shinkansen Railway Development Act.
• 1990November: construction begins on the Yamanashi maglev test line, on the planned route of the Chūō Shinkansen.
• 1997The 18.4 km initial section of the Yamanashi test line is completed; running tests begin 3 April, and an unmanned run reaches 550 km/h on 24 December.
• 20032 December: a three-car MLX01 set reaches 581 km/h in a manned run on the Yamanashi test track, certified by Guinness World Records the following year as a world speed record.
• 2007December: JR Central announces it will fund construction of the line between the Tokyo area and the Chūbu region on its own, without government financing, at an estimated total cost of about 5.1 trillion yen.
• 201026 October: JR Central announces the L0 Series train type for commercial operation at 505 km/h.
• 201127 May: government permission to proceed is granted as MLIT instructs JR Central, the named construction and operating entity, to build the line; the development plan decided the day before puts the construction cost of the whole Tokyo-Osaka line at over 9 trillion yen.
• 2013The full 42.8 km Yamanashi test line is completed and testing with the L0 Series service-type trainset begins; extension and upgrade work allowed top-speed running over longer periods.
• 201417 October: MLIT approves Plan C (under the Japanese Alps) for construction; the Tokyo (Shinagawa)-Nagoya groundbreaking is held on 17 December.
• 201521 April: on the Yamanashi test track the L0 Series sets a manned world rail speed record of 603 km/h, later certified by Guinness World Records.
• 201520 December: construction begins on the 25 km tunnel under the southern Japanese Alps, reaching about 1,400 m below the surface at its deepest point.
• 2020June: Shizuoka Prefecture officials deny permission to begin tunnel construction over Ōi River water concerns; the following week JR Central says a 2027 Tokyo-Nagoya opening is now difficult.
• 2024March: JR Central abandons the 2027 target, with opening not expected before 2034; Governor Kawakatsu announces his resignation on 2 April, and maglev proponent Yasutomo Suzuki wins the 26 May Shizuoka by-election.
• 2025The Tokyo-Nagoya opening outlook is reported to have slipped to no earlier than 2035.
• 2026January: Shizuoka's governor and JR Central sign a water-resources compensation agreement; on 26 March a prefectural special committee approves all 28 environmental conservation measures proposed by JR Central.