Determining the effectiveness of California's distracted driving regulations in decreasing motor vehicle crashes

We measured the impact on road fatalities and motor vehicle crashes of California's restrictions on use of cell phones and other electronic devices while driving. The Fatality Analysis Reporting System (FARS) and state department of transportation (DOT) monthly crash data were utilized to examine improvements in road safety from distracted driving legislation targeting teen and other drivers. The FARS records data on all fatal crashes on US public roads in which at least 1 fatality occurred. State DOT data on monthly number of motor vehicle crashes were also examined. Difference-in-differences regression was used to measure a ban's impact on roadway safety over time and in comparison with other states. Within 12 months of implementation of a ban on teen driver use of electronic devices, fatalities per 100 billion vehicle-miles traveled from teen driver-involved crashes decreased from 50.9 to 27.2. Difference-in-differences regression predicts that the ban decreased fatality rates by one-third in 2010. There is also evidence that California's universal ban on handheld cell phone use was effective in decreasing crashes. Generalized linear regression results suggest that California's ban on handheld cell phone use decreased monthly total motor vehicle crashes by over 4,000 compared to Texas and Florida—states without a universal cell phone ban. Study findings suggest restrictions on cell phone use for teen and other drivers were effective in improving roadway safety on California roadways. This study has important implications for state and federal policymakers who may be considering policies to tackle the public health threat of distracted driving.