The Shinkansen (新幹線, lit. "New Trunk Line" but better known in the West as the Bullet Train) is Japan's famous high speed train network.

History

It would be hard to overestimate the impact of the Shinkansen. In 1958, when the construction of the line started, Japan was still reeling over the devastation of World War II, and the West's popular image of blood-thirsty sadistic Japs had only recently been revised into an image of a nation of copycats, the words "Made in Japan" still a catchword for slightly awkward but functional and cheap copies of American products -- much like "Made in China" is today.

Pre-History

Interesting enough, as far back as 1940 there was a plan to build what even the Japanese called a Bullet Train (弾丸列車, dangan ressha) from Tokyo to Shimonoseki, at a maximum speed of 150 km/h -- poky by today's standards, but not compared to the then state-of-the-art 95 km/h Tsubame limited express. Some right of way was purchased and the digging of several tunnels commenced... but then came World War II and the project was put on hold. Some of the land and tunnels were reused for the Shinkansen though.

After the war, the Japanese economy bounced back quickly and the existing Tokaido line was soon reaching the limits of its capacity. The practical alternative would have been to four-track the existing line, but JNR pushed for and got the go-ahead to go for a dedicated high speed track instead.

and thanks to sekicho for tipping me off about this!

Tokaido Shinkansen (東海道新幹線)

So on October 1, 1964, just 5 years after construction started, the first Tokaido Shinkansen service (at a maximum speed of 210 km/h) between Tokyo and Shin-Osaka started, just in time for the Tokyo Olympics. The service shattered all existing speed records and shocked the rest of the world: it was the first incontrovertible proof that Japan could innovate as well as copy. It took 15 years for the second high speed train service -- France's TGV on September 27, 1981 -- to copy the feat.

The service was an immediate runaway success, with the 100 million passenger landmark reached in less than three years on July 13, 1967. The Tokyo-Osaka line remains JR's largest moneyspinner to this day. In 1975, HRH Queen Elizabeth II rode the Shinkansen from Nagoya to Tokyo; next year, the Shinkansen carried its one billionth passenger.

On March 14, 1992, JR started the new Nozomi superexpress service between Tokyo and Osaka, which crosses the distance of 515 kilometers in 2.5 hours.

Train names: Nozomi, Hikari, Kodama

San'yo Shinkansen (山陽新幹線)

The construction of extensions west of Osaka, along what is known in Japan as the San'yo coast, started almost immediately. Service to Okayama started in March 1972, while Hiroshima and Hakata were reached in January 1975.

The Nozomi service was later extended all the way to Hakata. At an average speed of 261.8 km/h, the fastest scheduled service in the world is the Nozomi between Hiroshima and Kokura.

The line is currently being extended through Kyushu to Kagoshima and Nagasaki, although it'll be 2010 or so before these are fully operational. (The Kagoshima-Yatsushiro segment, disconnected from the rest, will open in 2004 though.)

Train names: Nozomi, Hikari, Kodama

Tohoku Shinkansen (東北新幹線)

Up next was the Tohoku line to the north of Tokyo. The line to Morioka was opened in June 1982 and extended to Hachinohe in December 2002. An extension to Aomori is under construction, and in the far future it may reach up through the Seikan Tunnel to Hokkaido.

Train names: Yamabiko, Nasuno, Hayate

Joetsu Shinkansen (上越新幹線)

The Joetsu line to Niigata followed close on the heels of the Tohoku line, being opened to the public in November 1982. However, tunneling through Honshu was an extremely expensive exercise, and the population along the line has never been enough to financially support it. So why was it built? Most people point the finger at notoriously corrupt prime minister Kakuei Tanaka -- whose home constituency just happens to be Niigata.

Train names: Asahi, Tanigawa

Hokuriku Shinkansen (北陸新幹線)

The Hokuriku Shinkansen was opened on October 1, 1997 under the name Nagano Shinkansen; its initial terminus was thus, unsurprisingly, Nagano and once again a primary motive was the Nagano Winter Olympics of 1998.

The line is currently being extended along the Hokuriku coast to Toyama and Kanazawa, perhaps eventually looping back to Osaka.

Train names: Asano

Mini-Shinkansen

But the Hokuriku line seems to be last of the "full" Shinkansen lines. Instead, the 1990s saw two new so-called Mini Shinkansen lines open:

But don't be fooled -- these spur lines are just Shinkansen trains running on ordinary (if slightly upgraded) tracks at around 130 km/h.

Present

The Shinkansen has carried over 3 billion passengers to date with an amazing record of zero fatalities (excluding people falling off platforms and similar blatant acts of passenger stupidity). While travel is expensive -- Tokyo-Osaka by Nozomi, for example, costs almost ¥15,000 -- the supremely comfortable journey and the conveniently located train stations have ensured that air transport is a distant second for all cities connected by Shinkansen. The Japan Rail Pass also makes the Shinkansen more affordable for tourists in a hurry, although real cheapskates (like yours truly) tend to use night buses or hitchhike.

For a complete listing of all Shinkansen trainsets and technical details about track gauge and whatnot, look no further than morven's excellent Shinkansen Types.

Future

Extensions of the Sanyo line toward Kagoshima and the Tohoku line toward Hokkaido remain in various stages of construction, although these are unlikely to be reached before 2020.

A high-speed rail link to Narita airport -- already once started in 1974, but abandoned due to intractable difficulties over land ownership -- is once again under serious consideration.

The most significant future development possibility is the long-planned Chuo (Central) Shinkansen (中央新幹線), a maglev line connecting Tokyo, Nagoya and Osaka at speeds over 500 km/h. However, the exorbitant expense involved -- and the fact that Japan's brand of maglev technology is looking more and more out of date as time passes -- has so far kept these plans on hold. There are, however, already 18 km of test track in Yamanashi prefecture, which could in the future be integrated into the Chuo line.

References

http://www.h2.dion.ne.jp/~dajf/byunbyun/
Personal experience