Japan Sets Numeric Blood‑Alcohol Threshold for Drunk‑Driving Offences

A revision to Japan’s Automobile Driving Punishment Law took effect on July 21, introducing the first explicit numeric standard for drunk‑driving offences. The law defines a driver as intoxicated when the breath‑alcohol concentration reaches 0.5 mg per litre of exhaled air, making it the legal basis for the dangerous‑driving homicide charge. The amendment also sets clear speed‑excess thresholds: on roads with a limit of 60 km/h or less, exceeding 50 km/h is punishable, and on faster roads, exceeding 60 km/h triggers the same charge.

The change follows years of advocacy by victims’ families, notably after a 2021 fatal crash in Ōita where a driver travelling at 194 km/h collided with a runaway vehicle. Subsequent high‑profile cases in Akita and other prefectures highlighted the difficulty of applying the previously vague “dangerous driving” criteria. In response, the Tokyo Metropolitan Police have begun distributing informational flyers near major stations such as Ōi‑machi to alert the public to the new limits. The move aims to improve judicial clarity, accelerate investigations, and deter severe traffic accidents, which rose to six deaths in Tokyo in 2026 compared with the previous year.