The speed limit on a section of the Shin-Tomei Expressway was raised on Wednesday to 110 kph from 100 kph in a trial, set to last for at least a year, meant to gauge safety.
The change to a limit higher than 100 kph is the first since the nation's first expressway opened in 1963.
The trial — on a 50-km section of the roadway between the Shin-Shizuoka and Morikakegawa interchanges — comes in the wake of national debate on the topic.
The current plan calls for the upper limit to eventually be raised to 120 kph, with restrictions set during bad weather or in the event of accidents.
The trial change does not apply to trucks and other large freight vehicles, which still must adhere to a limit of 80 kph. To prevent accidents caused by the stark difference in speed, trucks will be limited to the left lane in certain sections.
The National Police Agency said in October last year that in addition to the Shin-Tomei trial, it would increase the limit on the Tohoku Expressway between the Hanamaki-Minami and Morioka-Minami interchanges. Authorities, including the Iwate Prefectural Police, are considering when to begin the trial on the 30-km section.
Also on Wednesday, the Shizuoka Prefectural Police expressway unit held a ceremony in the city of Shizuoka to demonstrate their resolve to step up traffic enforcement.
