Under the amended traffic law, cyclists caught using phones face up to six months in prison or fines of 100,000 yen ($656). Those caught cycling with breath alcohol levels above 0.15 milligrams per liter could face up to three years in prison or fines of 500,000 yen.
Police data shows accidents involving cyclists using mobile devices increased more than 50 percent to 454 cases between 2018 and 2022, compared with 295 incidents in the previous five-year period.
The new penalties significantly strengthen previous regulations, which varied by region and typically limited fines to 50,000 yen for mobile phone violations while cycling.