Purpose: The objective of this study was to investigate the relationship between a policy change in filing drunk driving charges in the city of Richardson, Texas, and subsequent arrests. Methods: The methods used in this study were: (1) the collection of data relating to drunk in public and drunk driving offenses from daily arrest logs of Richardson Police Department over a four year period; (2) the comparison of the drunk driving data prior to and after the policy change; (3) the comparison of drunk driving arrests with drunk in public arrests; (4) conducting personal interviews with individual officers; (5) collecting data on number of officers and calls for police service; and (6) tabulating arrest data by month and year. Findings: 1. The study indicates there was a strong correlation between administrative policy and officer performance. 2. There was a significant increase in drunk driving arrests in the year following the policy change compared to the previous year. 3. The significant increase applied only to drunk driving arrests and was not reflected in arrests for drunk in public. 4. A majority of the officers interviewed favored the more severe penalty for drunk drivers. 5. Two frequent reasons given for the increased arrests by the officers interviewed included more emphasis being placed on drunk drivers and better evidence for court due to the Breathalyzer machine. 6. A sharp increase in calls for police service had no apparent effect on the number of drunk driving arrests. 7. The study indicated that the increased arrests were not due to the novelty of the Breathalyzer.