The objective of this study, conducted in California and Delaware from November 2012 to June 2013, was to evaluate the effectiveness of three waves of enforcement that were conducted in support of laws banning the use of cell phones while driving. Enforcement methods included high-visibility enforcement and a media campaign that warned “Phone in one hand, ticket in the other.”
The media campaign proved to be effective as surveys of drivers revealed an increase in awareness that cell phone laws were being enforced. In addition, observational data regarding handheld driver cell phone use showed a decline of one-third from 4.1%to 2.7% in California (a 34% reduction); and a decline from 4.5% to 3% in Delaware (a 33% reduction). However, an analysis of crash data did not reveal any apparent effect on the incidence of distraction-related crashes in the same periods. It was concluded that high-visibility enforcement can be implemented over widespread, multijurisdictional areas and may reduce the number of people who use handheld cell phones while driving.
Chaudhary, N. K., Connolly, J., Tison, J., Solomon, M., & Elliott, K. (2015). Evaluation of the NHTSA Distracted Driving High-Visibility Enforcement Demonstration Projects in California and Delaware (No. DOT HS 812 108).