The study by Chaloupka and colleagues (1993) concluded that several drunk-driving laws, especially laws associated with relatively severe sanctions, can be effective deterrents to drinking and driving. In particular, the investigators found that whereas existing administrative per se license suspensions with relatively weak penalties have little effect on fatality rates, a relatively severe mandatory license suspension of 1 year significantly reduces drunk driving. Severe mandatory minimum fines and license sanctions upon conviction for DUI are also effective deterrents, although somewhat less effective than more immediate administrative penalties that can be imposed without court proceedings. In addition, both preliminary breath test laws, which raise the probability of arrest for DUI, and no-plea-bargaining provisions, which raise the expected penalties, deter drinking and driving. Reduced availability, resulting from both local prohibitions on alcohol sales and higher MLDAs, also can reduce drinking and driving, although the MLDA effects were limited to youths and young adults.
