Executive Summary

Objectives and Approach

The general objective of the project was to determine the effectiveness of establishing lower blood alcohol concentration (BAC) limits for convicted driving while intoxicated (DWI) offenders in one State. The project started with selecting the study State, involved developing State selection criteria, identifying potential case-study States that best met those criteria, and recommending a case-study State for consideration by the National Highway Traffic Safety Administration (NHTSA).

After NHTSA selected the study State (Maine), we prepared a plan for collecting and analyzing the data needed for the evaluation. The plan addressed both a process evaluation and an impact evaluation. The impact evaluation preceded along two lines, 1) an analysis of the general deterrent effect on alcohol-related fatal crashes, and 2) an analysis of the specific deterrent effect on recidivism.

Maine’s Lower BAC Law

Conviction of a first OUI offense1 in Maine results in an administrative license suspension under the condition that the offender does not drive with any measurable BAC for one year after reinstatement of the license. The law was passed in 1995 and was pre-ceded by a similar law passed in 1988 that prohibited such an offender from driving with a BAC of .05 or higher.

Reinstatement of the driver license is in the form of a conditional license issued by the Bureau of Motor Vehicles (BMV), which stipulates that the violator must have satisfactorily completed an alcohol educational program and, when required, has satisfactorily completed an approved alcohol treatment or rehabilitation program. The text of the stat-ute is contained in the Appendix to this report.


Data provided by the Maine Bureau of Motor Vehicles indicate that no large changes occurred in the level of general OUI enforcement activity after 1988. Arrests were fairly stable, averaging about 10,000 per year, and convictions trended down slightly, starting at 8,000 in 1988 and reaching 6,000 in 2000. Administrative per se actions against the driver license declined slightly to about 4,000 in the year 2000, but the BAC test refusal rate declined nearly 50%, from 18% to 10%.

Data from Maine’s driver records file indicate that convictions of repeat offenders in-creased slightly to about 37% of all OUI convictions, but this was probably due to an in-crease in the look-back period for determining the existence of prior OUI convictions.

License suspensions flowing from violations of the lower BAC law reached 250 in 1993 and settled down to about 200 in the year 2000, about half of which were for refusing to take a BAC test. Such suspensions amounted to less than 5% of all OUI-related administrative suspensions, and fewer than half were disposed of in administrative hearings. Of the 101 disposed cases in 2000, 41 of the suspensions were rescinded, 87% of which were due to the law enforcement officer failing to appear

Our discussion with staff from enforcement agencies and Maine’s Bureau of Motor Vehicles indicated that the lower BAC law did not place any significant burden on those agencies.

Our impact analysis used two neighboring States, Vermont and New Hampshire, to help account for factors other than the lower BAC law that may have influenced the occurrence of fatal crashes in Maine. Neither of these two comparison States had a lower BAC law, and both had an OUI enforcement environment similar to Maine’s. The impact analysis showed that in Maine, convicted OUI offenders in fatal crashes as a percent of all drivers in fatal crashes decreased from 12.9% to 7.1% (a decrease of 45%) after 1988, and decreased still more after 1995. At the same time, this percent increased slightly in the two comparison States.

With respect to alcohol-related fatal crashes, we found that for drivers at a BAC of .01-.09, convicted offenders as a percent of all such drivers in Maine stayed about the same over the 1988-2001 period, but increased gradually in the comparison States. But for drivers at .10+, this percent decreased from 18% in the 1982-1987 period to 15% in the 1996-2001 period; the percent increased from 15% to 17% in the comparison States. And after 1995, convicted offenders as a percent of all fatal crash-involved drivers in Maine decreased from 19% in 1996 to 11% in 2001. In the comparison States, this per-cent increased from 11% to 25%.

Our analysis of OUI recidivism in Maine revealed that the law affected recidivism very little. For offenders convicted in 1993-1994, the two-year recidivism rate was 14.6%. This fell to 13.6% for offenders convicted in 1996-1997. A similar decrease of 10.7% to 9.9% occurred for first offenders.

Finally, awareness of the lower BAC law in Maine was high in late 2002: 67% of the OUI offenders surveyed said they were aware of the law, and 45% knew about it before their most recent OUI convictions. Awareness was significantly higher among convicted offenders than among first offenders.

These measures of activity, impact, and awareness suggest strongly that Maine’s lower BAC law had a positive effect on OUI fatal crashes involving drivers with prior OUI offenses, and also on fatal crashes involving drivers with a BAC of .10 or more. No effect was noted for fatal-crash-involved convicted offenders with a lower BAC. Further, the small number of enforcement actions against violators of the lower BAC law and the absence of any meaningful reduction in OUI recidivism, suggest that the effect was a general deterrent effect rather than a specific deterrent effect.

Despite the strong indications of an effect, we cannot say unequivocally that the lower BAC law alone was responsible because of the concurrent existence of other OUI countermeasures. However, it can be said with some confidence that the law was an important element of Maine’s overall effort to decrease alcohol-impaired driving among convicted OUI offenders.


We conclude from Maine’s experience that, when included in a State’s arsenal of DWI countermeasures, a lower BAC law can be effective in reducing fatal crashes involving convicted DWI offenders, and in reducing alcohol-related fatal crashes involving convicted DWI offenders. We also conclude that such a law can be enacted and implemented with essentially no negative effects on a State’s DWI control system.

Driver licensing agencies in implementing States should include information on a person’s driver license indicating the existence of any condition requiring the person not to drive with any amount of alcohol in the blood. Also, driver-licensing agencies in implementing States should modify their driver records systems to include records of any violations of the State’s lower BAC law.

In implementing such a law, law enforcement agencies should train their officers in the provisions of the law, to be alert for signs of any drinking among stopped drivers, including those not visibly impaired, and to check for the existence of a driver license condition prohibiting driving with any amount of alcohol in the blood. In addition, the importance of attending administrative license revocation hearings should be stressed in officer training.

1Maine uses the term “operating under the influence of intoxicants” (OUI) instead of DWI for an alcohol-impaired driving offense.