Project Summary/Abstract The overall goal of the proposed project is to prevent young drivers from using their mobile phones (e.g., texting, calling or messaging through a third-party app) while driving. A novel technology is proposed to reduce the prevalence of distracted driving due to mobile phone use. The system will innovatively engage the senders of smartphone communications in the process of preventing distractions. The leading health threat to teens in the U.S. is motor vehicle crashes. Teens behind the wheel and their peer passengers account for one in every five deaths of 15 to 19 year-olds in the United States. According to police crash reports, cellphone use while driving among teen drivers greatly increases the likelihood of severe injuries in crashes. In 2018, 89% of teens owned a smartphone and 80% of teens are daily texters. Teens strongly intend to use their cellphone for calling or texting in general and are significantly more likely than adults to engage in text-messaging while driving. Teens know the dangers of distracted driving intellectually, yet continue to participate. Teens feel particularly strongly that they need to answer calls or reply to texts from a parent while they are driving and report the person who contacts them most often while they are driving is a parent. Many states are enacting laws to curb texting and cellphone use while driving; however, the continued prevalence of this activity even where it is illegal illustrates the need for novel solutions. Technological solutions, in the form of hardware or software that block texting and calling (interlocks) exist, but their effectiveness to date has been limited for a variety of reasons and these technologies only seek to affect the behavior of the driver. We propose a novel technological solution that engages both the driver and the person sending a message to the driver in the mission of preventing distracted driving.