The Canadian Charter of Rights and Freedoms has had considerable effect on Canada, politically, judicially and socially. One area in particular which has generated notable debate is its impact on policing. Prior to its entrenchment, many members of the law enforcement community opposed it as being an impediment to their efforts and a move towards the 'Americanization' of our criminal justice system. After living with the Charter for nearly fifteen years, we see that two of the areas of public policy most affected have indeed been those of legal rights and criminal procedures. While a popular perception of the Charter is that it undermines the enforcement of criminal law, the analysis here suggests that its influence may vary significantly across policy areas within this field. Focussing on the enforcement of impaired driving in Winnipeg, Manitoba, this study considers procedural changes necessitated by the Charter and/or Charter rulings, the effect of the increasing prominence of drunk driving as a social issue in Canada and police statistics as reflections of local and national trends. It further suggests that the Charter not only demonstrated the potential to impact on police effectiveness, but also coincided with a noticeable shift towards a due-process model of criminal justice. Both of these effects have influenced public and police perceptions of Canadian justice, which will have implications for the future management of the criminal justice system. However, the Charter has not compromised the ability of the police to enforce impaired driving laws.