Randomized trial on mobile technology to reduce young drivers’ cellphone use - PROJECT SUMMARY While motor vehicle crash risk is 2-6 times higher for all drivers engaging in cellphone use, cellphone use while driving is most prevalent among young drivers (18-24 years). Young drivers have both the highest phone use while driving and the highest crash rate per capita among all ages, but they are understudied. Technological solutions, including cellphone-blocking apps and driving mode (e.g., Apple’s “Do Not Disturb While Driving”), may be promising, but research on effectiveness remains sparse. Our pilot R21 found that a commercial app is effective in reducing cellphone use while driving, but had insufficient power to examine high-risk driving events. Few studies have examined driving mode or compared driving mode with a commercial app in reducing phone use and high-risk driving events. Therefore, we propose an R01 with objective to conduct a randomized controlled trial to determine the effects of a cellphone app and a driving mode intervention in reducing cellphone use and high-risk driving events in drivers aged 18-24 years. We hypothesize that cellphone use and high-risk driving events can be substantially reduced if a cellphone app or driving mode is active. We also hypothesize that the driving mode is as effective as the app. The aims of this project are to estimate the effects of the phone app and driving mode interventions in reducing calling, texting, and handheld phone use (Primary Aim 1), determine the effects of the phone app and driving mode interventions in reducing high-risk driving events (Primary Aim 2), and pilot test the feasibility of tracking traffic violations and crashes using existing databases (Exploratory Aim 3). A prospective, randomized, parallel-group, three-arm trial will be conducted. A total of 1,200 young drivers will be randomized to receive: (1) a commercial app (active FleetSafer) that blocks handheld phone use while driving, but allows emergency calls and phone use after pressing the passenger button; (2) a driving mode (provided by the cellphone manufacturer or service provider) that blocks handheld phone use while driving, but allows emergency calls and manual override or (3) an inactive FleetSafer app that permits and tracks calls and texts (controls). Participants will be studied for six months (month 1: baseline, month 2-6: intervention). The outcomes will include: (1) calling and texting while driving tracked by FleetSafer, and (2) handheld phone use while driving and high-risk driving events captured by a video camera. We will estimate the effectiveness of the app and driving mode interventions in reducing calling, texting, and high-risk driving events. Guided by our preliminary R21, this study is innovative as we focus on novel technological approaches to address the epidemic of cellphone-related distracted driving. We will employ proven video capture methods to identify high-risk driving events and assess the contribution of cellphone use. This study is significant, because the findings will provide information regarding the effectiveness of cellphone-blocking apps and driving modes in reducing cellphone use and high-risk driving behaviors in teens and young adults.