For many commuters who have had one too many after work, Uber has been a godsend, allowing over-the-limit passengers to stumble into a cab and get dropped off outside their door at the touch of a button.

But those days could be numbered after the taxi app invented a system for detecting drunk passengers and alerting drivers before they are picked up.

A patent submitted by Uber details a system that uses artificial intelligence to identify passengers exhibiting unusual behaviour and could even choose to deny them a ride if they are acting "uncharacteristically".

According to the patent, the algorithm would be able to look out for the user making typos, not precisely clicking on links and buttons, the way they are holding their phone, their walking speed and how long it takes to request a ride.

The system, branded a "tool for predators" by experts, will also look out for factors such as the time of day and where a ride is requested to determine a passenger's state. For example, it may decide a user is drunk if they are walking down a street that has a nightclub, in the early hours of the morning on the weekend, while clumsily typing.