Yoon Chang-ho Act (2018)
A 22-year-old soldier, Yoon Chang-ho, was killed by a drunk driver in Busan. Public anger pushed parliament to lower Korea's legal blood alcohol limit from 0.05% to 0.03% and toughen penalties, with the change taking effect in 2019.
Arrests and license revocations rose sharply as police adjusted to the stricter threshold.
Korea ended up with one of Asia's strictest blood alcohol limits, but repeat offenders remained a problem.
That gap, fewer crackdowns but more drivers caught seven or more times, is the specific problem the new labels are meant to address. Seoul again responded to drunk-driving harm with a rule change.
