The general opinion is that this is simply a cost saving exercise as they often have mass checks where a road is blocked off, and everyone has to blow in the bag – the cost in breathalysers to the authorities must be substantial, so they will now stop and ask you to use your own!
Blimey! I thought it was so citizens could check themselves to see if they were ok to drive. If it's for the constabulary to use motorists' own equipment on themselves I can foresee a huge potential black market for dodgy ones that don't change colour however drunk you are.
