This study used a controlled interruption time series to analyze the impact of Chica-go's COVID-19 policies on traffic safety, including stay-home orders, cautious reopening, gradual return, second wave of restrictions, restrictions lifed, and the new normal. The heterogeneity of policy effects among different population groups is also consid-ered. The results showed that: 1) Stay-at-home order and cautious opening policy had adverse effects on the casualty rate, and the effect of cautious opening policy was more significant;The stay-at-home order led to a spike in injury rates only in the fir...
