On Wednesday, the National Highway Traffic Safety Administration (NHTSA) proposed voluntary guidelines to smartphone manufacturers, asking them to help prevent distracted driving by blocking certain apps and functions for drivers.

In its guidance, the NHTSA has urged smartphone makers Apple, Samsung and others to consider the addition of a "driver mode" to their devices, for blocking drivers' access to certain apps and functions.

The NHTSA specifically asked smartphone makers to block some video displays for drivers, and also stop manual text entry while vehicles are on the roads.

As such, going by the NHTSA's guidance, smartphones when in "driver mode" would not be able to access social networking apps like Twitter or Snapchat. In addition, video would also be blocked, along with distracting graphics and scrolling text. Smartphone users would also not be able to use the keyboard of their handsets for sending text messages or emails while driving.

In proposing the addition of "driver mode," the NHTSA said that it envisions the mode as a "simplified user interface that is intended to minimize distraction experienced by a driver using that device."