Road safety is of increasing concern in developed countries because of the significant number of deaths and large economic losses. One tool commonly used by governments to deal with road accidents is the enactment of stricter policies and regulations. Drunk driving is one of the leading concerns in this field and several European countries have decided to lower their illegal Blood Alcohol Content levels to 0.5 mg/ml over the last decade. This study uses European panel-based data (CARE) for the period 1991-2003 for the first time to evaluate the effectiveness of this transition by applying the differences-in-differences method in a fixed effects estimation that allows for any pattern of correlation (Cluster-Robust). The results show positive policy impacts, particularly on certain groups of victims, such as young males in urban zones. However, there are reasons to expect a short lag in that effectiveness. (Contains 3 figures, 6 tables and 37 footnotes.)