Editing Multiple unit (section)

====Japan====
[[File:Shinkansen N700 z15.jpg|thumb|A [[N700 Series Shinkansen]] set in June 2008]]
In Japan almost all passenger trains, including the high-speed [[Shinkansen]], are of the multiple-unit (MU) type, with most locomotives now used solely in freight operations. Of the locomotive-hauled passenger services still in operation, the majority are tourist-oriented, such as the numerous steam-hauled trains operated seasonally on scenic lines throughout the country, as well as some of the luxury cruise trains.

Japan is a country of high population density with a large number of railway passengers in relatively small urban areas, and frequent operation of short-distance trains has been required. Therefore, the high acceleration ability and quick turnaround times of MUs have advantages, encouraging their development in this country. Additionally, the mountainous terrain gives the MUs an advantage on grades steeper than those found in most countries, particularly on small private lines many of which run from coastal cities to small towns in the mountains.

Most long-distance trains in Japan were operated by locomotives until the 1950s, but by utilizing and enhancing the technology of short-distance urban MU trains, long-distance express MU-type vehicles were developed and widely introduced starting in the mid-1950s. This work resulted in the original [[Shinkansen]] development which optimized all of the EMU's efficiencies to maximize speed. It was introduced upon completion of the [[Tokaido Shinkansen]] (literally "new trunk line") in 1964. By the 1970s, locomotive traction was regarded as slow and inefficient, and its use is now mostly limited to freight trains.

From 1999, there have been development efforts in [[M250 series|freight EMU]] technology, but it is currently used only for an express freight service on the [[Tokaido Main Line]] between Tokyo and Osaka. The government has been pushing for the adoption of freight EMU technology on energy efficiency grounds in the hope that widespread adoption could assist in meeting {{CO2}} emissions targets. The effort has been principally targeted at express package shipping that would otherwise travel by road.