Efforts to liberalize cannabis use and possession laws in the U.S. need to be appropriately informed about the impacts these laws would have on traffic safety. This project aims to meet this need by synthesizing the existing scientific evidence.
To fulfill this aim we will conduct a comprehensive literature review to examine the association between cannabis use, crash risk, and cannabis legislation as it pertains to different road users—of different genders, ages, demographic backgrounds, and type of crashes, over different U.S. regions and jurisdictions—and whether cannabis is consumed alone or conjointly with other substances. We will also review issues crucial to law enforcement and prosecution such as the effectiveness of drug impairment detection methods and the myriad of cannabis products available. We will also account for changes in the culture of cannabis use and crash risk over time. We will identify issues (i) for which there is ample consensus; (ii) with contradictory findings; and (iii) for which there is little or no research.
To address the limitations identified by the literature review, we propose a minimum of one but no more than two focus groups aimed at (1) gathering expert opinion on issues for which the literature showed contradictory or missing outcomes, and (2) discussing future scenarios that may occur with the rescheduling, decriminalization, and legalization of cannabis. The proposed qualitative study would allow a focused and candid treatment of challenging issues through the gathering of detailed information from experts even with opposing points of views.
In summary, this research applies an innovative mixture of quantitative and qualitative methods to assess current knowledge on cannabis use and crash risk and how this information may impact the rescheduling, decriminalization, and legalization of cannabis.
