Should we throw the book at ‘em? Charge combinations and conviction rates among alcohol-influenced drivers involved in motorcycle crashes

Abstract

Introduction: Motorcycle fatality rates are increasing, and impaired driving is a major contributing factor. Impaired driving laws are a main component of state efforts to reduce drunk driving, but motorcycle crash charge and conviction outcomes have yet to be studied. The purpose of this study was to evaluate driver charge and conviction outcomes following alcohol-related motorcycle crashes. Methods: Data for this study were drawn from Iowa crash, charge, and conviction data from 2011 to 2018. The study sample included 480 alcohol-influenced drivers (428 motorcyclists and 52 other vehicle drivers) involved in motorcycle crashes. Driver crash-related charges were categorized by type: Alcohol, Moving Violations, and Administrative/Miscellaneous. Factors associated with convictions were determined and estimated with multivariable logistic regression models. The main factor of interest was charge combination. Results: Over three-quarters (78.5%) of the 480 alcohol-influenced drivers in crashes received any charge type and 68.1% received an alcohol-related charge. Among drivers with any charge, 88.6% were convicted, and among drivers with alcohol charges, 87.2% were convicted on an alcohol charge. After adjusting for BAC, drivers with a combination of Alcohol, Administrative, and Moving Violation charges had more than three times the odds of conviction of any charge compared to drivers with alcohol only charges (OR = 3.21, 95% CI = 1.00–10.26). However, charge combinations had little impact on alcohol-related convictions. Conclusions: Convictions were more likely when the impaired driver was charged with multiple types of offenses than with a single offense. An increased variety of charges was not associated with greater rates of conviction on alcohol-specific charges, which had high conviction rates overall. Practical Applications: Law enforcement officers should be informed that lesser infractions impact driver conviction outcomes in alcohol-related crashes and procedures for issuing charges should be evaluated to assure equitable enforcement and to hold drivers accountable for unsafe driving behaviors.