Impaired driving has been a considerable social problem in the U.S. for decades, but efforts to reduce it have stalled after the initial reductions in the 1980’s. As a result, legislators continue to develop more polices aimed at deterring impaired driving. Although alcohol has historically been the focus of these efforts, recently there has been increased concern about marijuana impaired driving policies as well. However, alcohol and marijuana impaired driving differ in many ways. This paper explores the costs and benefits of new zero-tolerance policies such as the reduction of the per-se Blood Alcohol Concentration (BAC) level from .08 to .05 for alcohol and the establishment of similar per-se limits for marijuana. These policies are not based on actual impairment and reflect a net widening effect that will criminalize unimpaired drivers, divert criminal justice resources away from the most problematic impaired drivers, and will have little impact on impaired driving crashes. As such, they have the potential to do more harm than good.

数十年来，不良驾驶一直是美国的一个严重社会问题，但在 1980 年代初步减少之后，减少不良驾驶的努力就停滞不前了。因此，立法者继续制定更多旨在阻止不良驾驶的政策。尽管酒精在历史上一直是这些努力的重点，但最近人们对大麻损害驾驶政策的担忧也越来越多。然而，酒后驾驶和吸食大麻后的驾驶在许多方面有所不同。本文探讨了新的零容忍政策的成本和收益，例如将酒精本身的血液酒精浓度 (BAC) 水平从 0.08 降低到 0.05 以及建立类似的大麻本身限制。这些政 将刑事司法资源从问题最严重的受损驾驶员身上转移，对受损驾驶事故几乎没有影响。因此，它们可能弊大于利。