Traffic Tech #232: An Evaluation Of The .08 Per SE Law In Illinois Finds 13.7 Percent Fewer Fatal Crashes With Positive BACS |
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As of August 2000, 19 states plus the District of Columbia and Puerto Rico have enacted .08 per se laws. These laws make it illegal to drive with a blood alcohol concentration (BAC) at or above .08 percent. Several studies have been conducted evaluating the effectiveness of .08 laws. The preponderance of the evidence has demonstrated that .08 leads to a reduction in alcohol-related fatalities, especially when implemented in concert with a strong publicity campaign and highly visible enforcement.
One concern that has been voiced about the legislation is that it would lead to more DWI arrests (since now people with BACs in the .08 to .10 range are more likely to be arrested), and that additional arrests would overburden the criminal justice system.
As several states are considering legislation to lower their current .10 per se limit to .08, more information is needed on both the effectiveness of .08 legislation and the impact of the law on the enforcement and court systems.
The Pacific Institute for Research and Evaluation conducted a study for the National Highway Traffic Safety Administration (NHTSA) to examine Illinois' .08 per se law. The law became effective on July 2, 1997.
Evaluation of the Law
To determine the impact on alcohol-related crashes, the researchers conducted time series analyses using NHTSA's Fatality Analysis Reporting System (FARS) data. The FARS contains data about every reported motor vehicle traffic crash in the United States that involves a fatality.
Alcohol positive drivers involved in fatal crashes in the years 1988 through 1998 were analyzed. For comparison, the same time series analytic approach was used with data from five adjacent states (Indiana, Iowa, Kentucky, Missouri, and Wisconsin), all of which have .10 laws. In each case, the trend for nondrinking drivers involved in fatal crashes in the same period was entered as a covariate to reduce the influence of factors that are unrelated to drinking and driving (such as the number of vehicle miles driven).
Site visits were made to three communities to learn whether the .08 law caused any problems for local agencies. Police officers, prosecutors, judges, licensing agency representatives, and others were interviewed in Chicago, Peoria, and Springfield.
Alcohol-Related Fatalities Decline 13.7 Percent
The number of drivers with positive BACs (BAC>.00) in fatal crashes decreased 13.7 percent in Illinois after implementation of the .08 law. This is a statistically significant reduction, and included drivers at both low and high BACs. There were no significant changes in alcohol-related fatalities in the surrounding states during this time. The researchers estimated that the .08 law may have saved 47 lives in Illinois in 1998. The 13.7 percent reduction in Illinois is higher than typically has been found in other studies of the effects of .08 laws. It is likely, however, that the greatest effects of a new law are realized when it is first implemented. The effects may decrease in later years. This question will be addressed with additional analyses of the Illinois data in 2001.
Between 1996, the last full year before the .08 law, and 1998, Driving Under the Influence (DUI) arrests increased 11 percent in Illinois. The percentage of arrests involving drivers with BACs in the .08 to .09 range also increased, from less than 1 percent of all DUIs to 8 percent of DUI arrests.
Law Enforcement Officers' Perspective
Law enforcement officers did not express any major concerns about the new law, other than saying that arrest forms need to be revised and breath testing machines need to be recalibrated. Some officers expressed confusion over whether the Standardized Field Sobriety Test (SFST) is valid at .08, since it had originally been validated at the higher .10 level. The SFST is valid at .08 BAC, and NHTSA validated it for this BAC level (see Traffic Tech 196, March 1999). Law enforcement agencies were not overwhelmed with new arrests, and many officers said they felt more confident making arrests that used to be considered borderline at the .10 to .12 BAC levels.
Interestingly, officers said they thought that the number of persons who refused to submit to chemical testing increased, but the number of refusers actually decreased slightly.
Prosecutors' and Judges' Perspectives
Prosecutors and judges did not report any change in policies or procedures related to the .08 law. Like the police, they also reported a "lowering of the bar" with .10 cases no longer seen as being borderline. These cases are now challenged less often by defense attorneys.
BAC at Time of Arrest Averages .16
Persons in the sanctioning system (jail, probation, licensing office, treatment programs) reported no significant changes due to the new law. As the average BAC at time of arrest is .16 BAC (it was .18 prior to the .08 law), the number of administrative license hearings has been relatively unaffected by the .08 law.
Conclusions
Based on only a year and a half of experience, alcohol-related fatalities decreased 13.7 percent after implementation of the .08 per se law in Illinois. These data suggest that the law has had an impact in the state and has saved a significant number of lives. No major problems were reported by the local law enforcement or sanctioning systems. NHTSA will analyze the fatality data again in a year to determine the longer term impact of the .08 law.
HOW TO ORDER
For a copy of Effectiveness of the Illinois .08 Law (39 pages), write to the Office of Research and Traffic Records, NHTSA, NTS-31, 400 Seventh Street, S.W., Washington, DC 20590 or send a fax to (202) 366-7096, or download from www.nhtsa.dot.gov Amy Berning was the contract manager for this project.
U.S. Department
of Transportation
National Highway
Traffic Safety
Administration
400 Seventh Street, S.W. NTS-31
Washington, DC 20590
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Linda Cosgrove, Ph.D., Editor, Evaluation Staff
Traffic Safety Programs
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