Speed increases Tōhoku Shinkansen E5 series trains, capable of up to , initially limited to , were introduced on the
Tōhoku Shinkansen in March 2011. Operation at the maximum speed of between and on this route commenced on 16 March 2013. It reduced the journey time to around 3 hours for trains from Tokyo to Shin-Aomori, a distance of . Extensive trials using the
Fastech 360 test trains have shown that operation at is not feasible because of problems of
noise pollution (particularly
tunnel boom), overhead wire wear, and braking distances. On 30 October 2012, JR East announced that it was pursuing research and development to increase speeds to on the Tohoku Shinkansen by 2020. The
ALFA-X is undergoing testing.
Hokkaido Shinkansen Upon commencement of services in 2016, the maximum speed on the approximately
dual gauge section of the
Hokkaido Shinkansen (including through the
Seikan Tunnel) was , which was increased to by March 2019. There are approximately 50 freight trains using the dual gauge section each day, so limiting the travel of such trains to times outside of Shinkansen services is not an option. Because of this and other weather-related factors cited by JR East and JR Hokkaido, the fastest journey time between Tokyo and Shin-Hakodate-Hokuto is 3 hours, 57 minutes. During the 2020–21 New Year Holiday period, certain Shinkansen services were operated at on the dual gauge section and was proposed again for the
Golden Week Holiday period from 3–6 May 2021, due to fewer freight trains operating. There are further plans to extend the line from Tsuruga to Osaka, with the Obama-Kyoto route chosen by the government on 20 December 2016, after a government committee investigated the five nominated routes. Construction of the extension beyond Tsuruga is not expected to commence before 2030, with a projected 15-year construction period. On 6 March 2017 the government committee announced the chosen route from Kyoto to Shin-Osaka is to be via
Kyotanabe, with a station at on the
Katamachi Line.
Abandoned interim Gauge Change plans To extend the benefits of the Hokuriku Shinkansen to stations west of Tsuruga before the line to Osaka is completed, JR West was working in partnership with Talgo on the development of a
Gauge Change Train (CGT) capable of operating under both the 25 kV AC electrification used on the Shinkansen and the 1.5 kV DC system employed on conventional lines. A trial of the proposed bogie was undertaken on a purpose-built gauge-changer at Tsuruga, but it was unsuccessful and the plans were abandoned.
Tohoku extension/Hokkaido Shinkansen The
Hokkaido Shinkansen forms an extension of the Tohoku Shinkansen north of to
Shin-Hakodate-Hokuto Station (north of the
Hokkaido city of
Hakodate) through the
Seikan Tunnel, which was converted to dual gauge as part of the project, opening in March 2016.
JR Hokkaido is extending the Hokkaido Shinkansen from Shin-Hakodate-Hokuto to to open by 2038. The extension will be approximately 76% in tunnels, including major tunnels such as Toshima (~) Oshima (~), Teine (~) and Shiribeshi (~). Although an extension from Sapporo to
Asahikawa was included in the 1973 list of planned lines, at this time it is unknown whether the Hokkaido Shinkansen will be extended beyond Sapporo.
Nishi Kyushu Shinkansen JR Kyushu opened the Nishi Kyushu Shinkansen from to (built to full Shinkansen standard) on 23 September 2022, with the existing narrow-gauge section between Shin-Tosu and Takeo Onsen proposed to be upgraded as part of this project. This proposal initially involved introducing
Gauge Change Trains (GCT) travelling from Hakata to Shin-Tosu () on the existing Kyushu Shinkansen line, then passing through a specific gauge changing (standard to narrow) section of track linking to the existing
Nagasaki Main Line, along which it would travel to Hizen Yamaguchi (), then onto the
Sasebo Line to Takeo-Onsen (), where another gauge changing section (narrow to standard) would lead onto the final Shinkansen line to Nagasaki (). However, significant technical issues with the axles of the GCT resulted in its cancellation. On 28 October 2020, JR Kyushu announced it would utilize a 6-car version of the N700S for the isolated Shinkansen section from Nagasaki, with 'cross platform' change to a relay service at Takeo Onsen station to connect to Hakata. JR Kyushu also announced the service would continue to use the name 'Kamome' for the Hakata-Nagasaki service, which has been in use since 1961. The Shinkansen line shortens the distance between Hakata and Nagasaki by 6.2% (), and while only 64% of the route is built to full Shinkansen standards, it eliminated the slowest sections of the previous narrow-gauge route. As part of the GCT proposal, the section of single track between Hizen Yamaguchi and Takeo Onsen was proposed to be duplicated. However, due to the issues with the development of the GCT, the proposal did not advance. The initial section between Nagasaki and Takeo Onsen opened on 23 September 2022.
Maglev (Chūō Shinkansen) Maglev trains have been undertaking test runs on the Yamanashi test track since 1997, running at speeds of over . As a result of this extensive testing, maglev technology is almost ready for public usage. An extension of the test track from was completed in June 2013, enabling extended high-speed running trials to commence in August 2013. This section will be incorporated into the
Chūō Shinkansen which will eventually link Tokyo to Osaka. Construction of the
Shinagawa to
Nagoya section began in 2014, with 86% of the route to be in tunnels. Plans were approved in 2017 for the Chūō Shinkansen to begin at
Tokyo Station, rather than
Shinagawa Station as initially planned due to difficulties in securing land. JR Central originally aimed to begin commercial service between Tokyo and Nagoya in 2027. However, in 2024, Central Japan Railway Co President Shunsuke Niwa said that due to construction delays a 2027 opening was now impossible and it is not expected to open until at least 2034. While the government has granted approval for the shortest route between Tokyo and Nagoya, some prefectural governments, particularly Nagano, lobbied to have the line routed farther north to serve the city of
Chino and either
Ina or . However, that would increase both the travel time (from Tokyo to Nagoya) and the cost of construction. JR Central has confirmed it will construct the line through
Kanagawa Prefecture, and terminate at
Shinagawa Station. The route for the Nagoya to Osaka section is also contested. It is planned to go via
Nara, about south of
Kyoto. Kyoto is lobbying to have the route moved north and be largely aligned with the existing
Tokaido Shinkansen, which services Kyoto and not Nara.
Mini-Shinkansen is the name given to the routes where former narrow-gauge lines have been converted to standard gauge to allow Shinkansen trains to travel to cities without the expense of constructing full Shinkansen standard lines. Two mini-shinkansen routes have been constructed: the
Yamagata Shinkansen and
Akita Shinkansen. Shinkansen services to these lines traverse the
Tohoku Shinkansen line from Tokyo before branching off to traditional main lines. On both the Yamagata/Shinjo and Akita lines, the narrow-gauge lines were regauged, resulting in the local services being operated by
standard-gauge versions of suburban/interurban rolling stock. On the Akita line between Omagari and Akita, one of the two narrow-gauge lines was regauged, and a section of the remaining narrow-gauge line is dual gauge, providing opportunity for Shinkansen services to pass each other without stopping. The maximum speed on these lines is , however the overall travel time to/from Tokyo is improved due to the elimination of the need for passengers to change trains at
Fukushima and
Morioka respectively. As the
loading gauge (size of the train that can travel on a line) was not altered when the rail gauge was widened, only Shinkansen trains specially built for these routes can travel on the lines. They are the E3 and E6 series trains. Whilst no further Mini-shinkansen routes have been proposed, it remains an option for providing Shinkansen services to cities on the narrow-gauge network.
Proposed Ou Base Tunnel Construction of a
base tunnel on the
Yamagata Shinkansen is proposed, with JR East having undertaken a survey of a planned route from Niwasaka to Sekine, just south of Yonezawa station. of the proposed line would be in tunnel, mostly to the north of the existing Fukushima – Yamagata section. To be built on an improved alignment, the tunnel would lower journey times between Fukushima and Yamagata by ~10 min due to a proposed line speed of up to 200 km/h. The tunnel would avoid the Itaya Toge pass through the
Ōu Mountains west of Fukushima. Gradients range from 3.0% to 3.8% and the line reaches an altitude of . The curvature and steep grades of the current line limit train speeds to or less, and it is vulnerable to heavy rain and snowfall as well as high winds. Between 2011 and 2017 a total of 410 Yamagata mini-Shinkansen services were either suspended or delayed, and 40% of these incidents occurred on the line over the Itaya Toge pass. If the base tunnel is authorised, detailed design would take five years and construction another 15 years. The cost could increase by if the tunnel were to be built with a cross-section large enough to permit the line to be upgraded to the full Shinkansen loading gauge.
Gauge Change Train This is the name for the concept of using a single train that is designed to travel on both narrow-gauge railway lines and the standard gauge used by Shinkansen train services in Japan. The trucks/bogies of the Gauge Change Train (GCT) allow the wheels to be unlocked from the axles, narrowed or widened as necessary, and then relocked. This allows a GCT to traverse both standard-gauge and narrow-gauge tracks without the expense of regauging lines. Three test trains were constructed, with the second set having completed reliability trials on the
Yosan Line east of
Matsuyama (in
Shikoku) in September 2013. The third set was undertaking gauge changing trials at
Shin-Yatsushiro Station (on
Kyushu), commencing in 2014 for a proposed three-year period, however testing was suspended in December 2014 after accumulating approximating , following the discovery of defective thrust bearing oil seals on the bogies. The train was being trialled between
Kumamoto, travelling on the narrow-gauge line to Shin-Yatsushiro, where a gauge changer was installed, so the GCT could be trialled on the Shinkansen line to
Kagoshima. It was anticipated the train would travel approximately over the three-year trial. A new "full standard" Shinkansen line was opened in 2022 from Takeo Onsen to , with the Shin-Tosu – Takeo Onsen section of the
Nishi Kyushu Shinkansen remaining narrow gauge. GCTs were proposed to provide Shinkansen service from the line's opening, however with the GCT being cancelled, JR Kyushu announced it would provide an interim
'relay' service. There are currently no further proposals for use of the GCT, nor any development work on it. == Competition with air ==