The eastern portion, the Chūō East Line (, ), is operated by the East Japan Railway Company (JR East), while the western portion, the Chūō West Line (, ), is operated by the Central Japan Railway Company (JR Central). The dividing point between the two companies is , where express trains from both operators continue to the Shinonoi Line towards the cities of Matsumoto and Nagano. Compared to the huge urban areas at either end of the Chūō Line, its central portion is very lightly traveled; the Shiojiri-Nakatsugawa corridor is only served by twice-hourly local and hourly limited express trains.