As it stands, or as it might stand if this recommendation goes through...
If a copper pulls someone up for using a phone, because they just happen to have spotted them doing it, it's a fine (£60?) and 6? (or 3?) points. If a person is seen driving erratically or is in an accident, and phone use is proved to be an issue, they could could go jail, because it would now be classed as Dangerous Driving. Of course, the damage may well be done, if that person's actions have hurt or killed someone, or damaged their property....
My question is: If a copper pulls someone up in the first situation, is the Fixed Penalty Ticket the most they can do, or do they have the power to take it to court if they choose? Seems to me that if someone has to cause an accident to be nicked for dangerous driving, the damage is done, and they may well have learned their lesson anyway. It's those who think "well, I'm alright, I can manage" that are the danger, because they don't know they can't manage until they hit someone, no matter how much you tell them. Most people, I think, assume that they are better than average drivers...
In the long run, why not build signal blockers into cars? I have no idea if such a thing exists, but if you could stop a phone working inside a car, there's the answer. (although there's a safety issue in terms of breakdowns, I admit). And then they could build them into cinemas and so on as well...