Do Not Disturb While Driving – use of cellphone blockers among adult drivers

Reagan, Ian J. / Cicchino, Jessica B.
Insurance Institute for Highway Safety
December 2018

Introduction: Cellphone blockers are an emerging countermeasure for limiting driver distraction. This study focused on Apple’s Do Not Disturb While Driving (DND) application because of its unique rollout where owners were prompted to try it as part of a software update.
Method: A telephone survey of 800 adult drivers who own smartphones was conducted to estimate cellphone blocker use. Respondents were asked about acceptance of blockers and reasons for nonuse. Logistic regression estimated the relationship between cellphone blocker use and the likelihood of reported engagement in cellphone behaviors while driving, controlling for other factors that could affect these behaviors.
Results: Only 20.5% of respondents with DND-compatible iPhones had the application set to activate automatically when driving or when connected to a vehicle’s Bluetooth. Among respondents with DND-incompatible phones, 18.7% of respondents reported having an alternative non-DND blocker, and only half of these reported turning it on while driving at least three quarters of the time. Thirty-nine percent of drivers with DND-compatible iPhones who had DND set to turn on when manually activated trip-by-trip said they would not be frustrated if they received another prompt to use the application, and 26.7% reported they would be likely or very likely to try it if they received another prompt. Respondents classified as using blockers were less likely to report conducting phone calls and sending emails or text while driving than respondents who did not use them, although the results varied between those with DND and other blockers.
Conclusion: Cellphone blockers have the potential to limit cellphone distractions, although it is uncertain to what degree the differences in behaviors reported here are caused by blockers or are a result of drivers selecting to use blockers because they are averse to phone use while driving.