PMR Radio, an interesting thought

A colleague of mine came up with an interesting idea today, he said that if every Taxi was fitted with a PMR Radio or every driver carried a handheld PMR radio it could make driving a Taxi in London a lot easier which when you think could be quite a good idea. It would mean that drivers could relay information to each other about when taxis are required a certain ranks or any other location and due to the short range of PMR only the drivers in the local vicinity would receive the message. This idea could also help doorman at hotels that are off of the beaten track to locate taxis with ease without even walking out onto the street, this is such a simple idea that I am surprised that no one has thought of it before.