It's a cheap headline grabber, that's all. The Police can already pull you over for careless/dangerous driving, this streamlines the process slightly after they have done so, but misses the main point.
Plod has to be there in the first place.
I ride my Motorbike to London most days (60 - miles each way) & the standard of some peoples driving is atrocious. On the phone, tailgating, wandering all over the lane.
If they saw police cars driving along, or that had pulled people over, I think they'd be less likely to do it. My highlight recently was someone pulling out right in front of me - didn't see me because they were typing on their Ipad!!
We need more Police to enforce the laws that already exist, rather than more laws to be ignored...