Despite its reputation as an out-of-the-way city, Oita has multiple points of access.
By plane
Located approximately 25 miles northeast of Beppu, Oita Airport is the main commercial airport in Oita Prefecture and has daily services to and from Tokyo, Osaka both Kansai and Itami and Nagoya by both JAL (http://www.jal.com/) and ANA (http://www.fly-ana.com/) as well as a single international flight to Seoul, Korea with Korean Air (http://www.koreanair.com/)
Travel between the airport and surrounding cities and towns are handled by bus and hovercraft suspended operations in September 2009, unfortunately lacking any train access as of yet. The bus has an approximate travel time of 45 and 60 minutes to Beppu and Oita, respectively. The hovercraft trip is significantly faster, only taking 25 minutes, and deposits passengers at a landing in Oita just east of the Oita River. Access between this landing and the city's downtown takes approximately 10 minutes via taxi or bus and about 1 hour on foot.
By train
Three JR Kyushu train lines run through Oita Station, located downtown: Nippo Honsen, Hohi Honsen and Kyudai Honsen. The Nippo Honsen could be considered Oita's main rail access line, running JR Kyushu's Sonic trains from Hakata Station and reaching as far south as Miyazaki. Sonic express trains take approximately two hours to and from Hakata Station. The Kyudai Honsen has local service running to the west and reaching as far as Saga Prefecture. Finally, the Hohi Honsen runs local and express service as far as Kumamoto City, Kumamoto Prefecture.
By ship
Diamond Ferry runs a daily ferry between Oita and Kobe/Osaka, making stops in Matsuyama, Ehime Prefecture and Takamatsu, Kagawa Prefecture. This service is a "sleeper ship", starting in Osaka in the late afternoon and running through the night until passengers disembark in the morning.
By car
Oita is most easily accessed by car via the East Kyushu Expressway, a well-maintained toll highway that runs from Fukuoka and through Oita, as far as the city of Usuki. Though expensive to use the highway is undeniably swift.
By bus
Buses from virtually every major city on Kyushu have service to Oita, the main ones being the multiple highway buses that run to and from Fukuoka. Oita Bus, Oita Kotsu, Kamenoi Bus and a handful of others offer this highway service and travel time is approximately two hours, nearly identical to JR Kyushu's Sonic.