An Investigation of the Neighborhood Density of Cannabis Outlets and its Effect on Traffic Crashes

Project Summary In the past decade, fatal traffic crashes involving cannabis have doubled in the United States (US). This trend is associated with state policies that expand access to adult use of cannabis through the legal market. There is a societal need for a) examination into local cannabis policy, the ensuing neighborhood density of cannabis outlets, and their relationship to social determinants of health and traffic crashes; and b) investigators who are trained to execute such research and translate findings into public health action. The applicant, a doctoral candidate in epidemiology at Michigan State University, leverages his interdisciplinary mentorship team of experts, optimal training environment, and injury prevention research experience to propose this predoctoral fellowship that will address these needs. Firstly, this research aims to 1) describe spatial associations between census tract cannabis outlet density and social determinants of health (e.g., alcohol outlet co-location and community deprivation); 2) estimate the spatiotemporal relationship between census tract cannabis outlet density and traffic crashes; and 3) estimate the effect that municipality-level policies permitting the operation of adult-use cannabis outlets have on traffic crashes. To complete these aims, the applicant will complete the creation of a novel spatiotemporal dataset that aggregates publicly available cannabis outlet and traffic crash data within Michigan, the first state in the Midwest region of the US to legalize adult-use of cannabis. This research will implement innovative spatiotemporal and econometric modeling. Successful completion of these aims will inform NIDA’s priority research objectives (NOT-DA-22-003) and focus area goals (1.2) regarding the impact that local cannabis policy has on public health. Moreso, this research is formally supported by the State of Michigan Office of Highway and Safety Planning (MOHSP). Project results will be directly communicated to MOHSP and will have an immediate impact on local, state, and national cannabis policy making. Secondly, this fellowship’s comprehensive training plan will facilitate the applicant’s long-term career goal of becoming an independent substance use and injury science epidemiologist with expertise in the nascent cannabis regulatory environment. Through formal coursework, workshops, seminars, conference presentations, and structured mentorship, the applicant will cultivate an interdisciplinary methodological toolkit, gaining essential skills in substance use and spatial epidemiology, injury prevention science, policy evaluation through econometrics, and professional development. The advising team comprises substantive experts in cannabis use epidemiology (Dr. Kipling Bohnert, Proposal Sponsor), injury prevention (Drs. Jason Goldstick and Christopher Morrison), geography (Dr. Richard Sadler), policy evaluation (Dr. Claire Margerison), traffic crash research (Dr. Morrison), and spatiotemporal statistics (Drs. Goldstick, Sadler, and Morrison). This fellowship will effectively prepare the applicant, Matthew Myers, for a career as an independent substance use and injury prevention epidemiologist and will establish an evidence base used to prioritize public health in cannabis-related policy making.