The Tsukuba Express line linking the 58.3 km between Tokyo's Akihabara district and Tsukuba, Ibaraki Prefecture, began Wednesday, connecting the two points in 45 minutes.
The first train left Tsukuba Station shortly after 5 a.m. with some 1,200 passengers.
The service suffered its first trouble when a train overran a platform by 30 meters at Kitasenju Station in Tokyo, causing a delay of about three minutes.
It took 20 years for the line to be completed; it was originally proposed by the Council for Transport Policy in 1985. It is operated by Metropolitan Intercity Railway Co., a joint public-private venture.
The service connects Saitama, Chiba and Ibaraki prefectures and Tokyo with 20 stations, aiming to carry about 135,000 passengers a day.
The line expects the daily number of passengers to increase to 270,000 in five years, as new houses and apartment buildings are rapidly being built along its route.
The minimum fare is 160 yen, while a ride between Akihabara and Tsukuba stations costs 1,150 yen.
The railroad has no crossings because it runs either underground or on elevated tracks. The trains are run by an automatic train operation system, with each train manned by a single driver.
When the overrun at Kitasenju Station took place, the driver had switched off the automatic system and was manually adjusting the speed as the train entered a curve into the station.
All station platforms are equipped with automatic doors touted as more safe for passengers. The service also comes with a wireless local area network currently being used on a trial basis.
