Apple has patented a system that would provide a “lock-out mechanism” to stop drivers texting or using other functions that may cause distraction on their smartphones while on the move.

The patent describes how a device could determine if it was moving by looking at data from GPS, phone towers or even images from the camera. Visual clues would enable the device to calculate if its owner was driving the car or merely a passenger, imposing limits in the former case but not the latter.

Algorithms would look for a steering wheel in close proximity to the camera, or search for the number of faces – only one visible person would indicate that the user must be the one driving. It could also differentiate between the interior of a car and a train carriage or seat on a bus, where safety features would be unnecessary.

The application even suggests that the accelorometer could be used to detect when an unscrupulous driver was tilting the phone so as to not reveal the steering wheel and evade the safety feature. Sensing the speed of travel would also prevent the limits from kicking-in if the user was just walking.

There are several Android apps which aim to perform a similar function, but Apple’s tight controls on what apps can and cannot access on the iPhone’s hardware have largely prevented similar software from launching on the iOS platform.