Evidence-Based Policing Matrix
Jurisdiction – Fell et al. (2005)
Study Reference:
Location in the Matrix; Methodological Rigor; Outcome:
Jurisdictions; Focused; Proactive; Moderately Rigorous; Mixed effects
What police practice or strategy was examined?
Four separate demonstration projects in four states aiming at reducing impaired driving were examined. The Georgia Highway Safety Offices used publication and media efforts and also conducted 2,837 sobriety checkpoints over 14 months. The Louisiana State Police and the Louisiana Highway Safety Commission targeted 16 parishes out of 64 in the state, using media and publication approaches as well 217 saturation patrols and then sobriety checkpoints over 10 months. The Pennsylvania Department of Transportation targeted 14 out of 67 counties, using public education programs and media outlets, as well as 150 sobriety checkpoints, 150 reduced staffing checkpoints, 480 roving patrols, and 360 mobile awareness patrols over 14 months. The Tennessee Highway Patrol used publication and media efforts, and conducted 535 sobriety checkpoints, 270 enforcement roadblocks, and 270 roving and saturation patrols over 14 months.
How was the intervention evaluated?
Telephone surveys of a random sample (N=1,000) of the driving population in each of the four demonstration states were conducted to determine the extent to which the alcohol enforcement programs affected the awareness, attitudes, and drinking-and-driving behavior of motorists. The surveys were conducted in three waves, prior to the program implementation, midway through the program, and one year after the initial survey. Data was also collected regarding alcohol-related fatal crashes from the Fatality Analysis Reporting System (FARS) 15 years before the program, which was aggregated into 90 bimonthly totals for each state. 20 separate time-series analyses were performed to compare the trends in treatment jurisdictions with those in within-state comparison jurisdictions, neighboring states, and the rest of the nation.
What were the key findings?
Georgia experienced a significant decrease in the ratio of drinking drivers to nondrinking drivers in fatal crashes (14%), accompanied by a non-significant 5% decrease in alcohol-related fatalities. In Louisiana, there were no significant differences in the ratio of drinking drivers to nondrinking drivers in fatal crashes between parishes receiving and not receiving the intervention (although the implementation of the intervention was not consistent). In Pennsylvania, there were decreases in all measures when compared to similar states, but none of the differences were significant. Tennessee experienced a significant decrease in the ratio of drinking drivers to nondrinking drivers in fatal crashes (10.6%) and no change in the others relative to the changes found in the comparison states. Finally, the telephone survey results showed some positive indications regarding public awareness of the program and drinking-and-driving behaviors.
What were the implications for law enforcement?
The authors suggest that states can expect significant decreases in impaired driving if they use a sobriety checkpoint model that includes: 1) a statewide effort; 2) numerous checkpoints consistently conducted throughout the year; 3) intensive publicity about the enforcement especially paid advertising; and 4) trained and equipped law enforcement officials. Highly publicized sobriety checkpoints conducted weekly throughout a state appear to be one of the most effective strategies for immediately reducing impaired driving fatalities.
Where can I find more information about this intervention, similar types of intervention, or related studies?