RESUMO
OBJECTIVE: The concentration of drugs in a driver's system can change between an impaired driving arrest or crash and the collection of a biological specimen for drug testing. Accordingly, delays in specimen collection can result in the loss of critical information that has the potential to affect impaired driving prosecution. The objectives of the study were: (1) to identify factors that influence the time between impaired-driving violations and specimen collections (time-to-collection) among crash-involved drivers, and (2) to consider how such delays affect measured concentrations of drugs, particularly with respect to common drug per se limits. METHOD: Study data included blood toxicology results and crash-related information from 8,923 drivers who were involved in crashes and arrested for impaired driving in Wisconsin between 2019 and 2021. Analyses examined how crash timing and severity influenced time-to-collection and the effects of delays in specimen collection on blood alcohol concentrations (BACs) and blood delta-9-tetrahydrocannabinol (THC) concentrations. RESULTS: The mean time-to-collection for the entire sample was 1.80 h. Crash severity had a significant effect on time-to-collection with crashes involving a fatality having the longest duration (M = 2.35 h) followed by injury crashes (M = 2.06 h) and noninjury crashes (M = 1.69 h). Time of day also affected time-to-collection; late night and early morning hours were associated with shorter durations. Both BAC (r = -0.11) and blood THC concentrations (r = -0.16) were significantly negatively correlated with time-to-collection. CONCLUSIONS: Crash severity and the time of day at which a crash occurs can result in delays in the collection of blood specimens after impaired driving arrests. Because drugs often continue to be metabolized and eliminated between arrest and biological specimen collection, measured concentrations may not represent the concentrations of drugs that were present at the time of driving. This has the potential to affect drug-impaired driving prosecution, particularly in jurisdictions whose laws specify per se impairment thresholds.
RESUMO
BACKGROUND: Accidents in degraded visibility continue to account for a disproportionately large number of fatal crashes and fatalities in general aviation (GA). However, the relatively small percentage of these crashes annually suggests that even a small reduction in the number of crashes can result in a large reduction in associated fatalities. OBJECTIVE: This study identified risk factors associated with GA accidents that occur in degraded visibility. METHODS: Data collected during 72 National Transportation Safety Board investigations of GA accidents were compared with data collected from 135 control flights matched on weather conditions, location, time, and rules of flight. Study variables included pilot demographics, experience, testing and accident histories, and the purpose and length of flights. Initial comparisons were conducted using Chi-square analyses, followed by the development of a logistic regression model. RESULTS: Univariate analyses identified significant differences in pilot age at accident, age at initial certification, certificate level, instrument rating, testing performance, and previous accident involvement. There were also significant differences between groups related to aircraft ownership, purpose of flight, and intended flight length. The logistic regression revealed significant increased risk for pilots initially certified after age 25 [odds ratio (OR) 4.5, 95% confidence interval (CI) 1.9-10.81, without instrument ratings (OR 4.8, 95% CI 1.8-12.8), with prior accidents/incidents (OR 3.1, 95% CI 1.1-8.7), and for intended flights longer than 300 nmi (OR 4.6, 95% CI 1.6-13.8). CONCLUSIONS: Certain risk factors (e.g., instrument rating) were consistent with previous research, while others (e.g., age at certification) raise questions for future research.
