Mobile phone use while driving is common but it is dangerous due to its potential for causing distracted driving and subsequent crashes. Due to the number of crashes that are related to conducting calls on a phone and texting while driving, some jurisdictions have made the use of calling on a phone while driving illegal in an attempt to curb the practice, with varying levels of efficacy. Many jurisdictions have enacted laws making handheld mobile phone use illegal. Many jurisdictions allow use of a hands-free device. Driving while using a hands-free device has been found by some studies to provide little to no benefit versus holding the device itself and carrying on a conversation. In some cases restrictions are directed only at minors, those who are newly qualified license holders, or to drivers in school zones. In addition to voice calling, activities such as texting while driving, web browsing, playing video games, or phone use in general may also increase the risk of a crash.

Distracted driving is the act of driving while engaging in other activities which distract the driver's attention away from the road. Distractions are shown to compromise the safety of the driver, passengers, pedestrians, and people in other vehicles.