Disclosed are various embodiments for restricting usage of a mobile device when a user is driving a vehicle. In one embodiment, it is determined that a mobile device is in use by a driver of an active vehicle. A functionality of the mobile device is then restricted based at least in part on determining that the mobile device is in use by the driver of the active vehicle. For example, a touch screen of the mobile device may be disabled, and the use of a hands-free interface may be made mandatory.