Anybody else suffering a credibility gap over the amazing claims being made for the “car share cameras” that are going to police the brave new world of paid-for motorway fastlanes?

Now the Government’s much-vaunted plans to introduce national road charging appear to have collapsed – or at the very least lost a couple of wheels – we’re now faced with the equally daft proposal to reserve priority lanes on motorways for those who can pay to travel in them or for vehicles carrying more than one occupant.

These will be policed, we’re assured, by the new wave of super-clever “dtect” cameras that will be used to count the number of occupants in the car. And then, if a number greater than 1 isn’t found, it will presumably consult the all-knowing Swansea database and stick a fine in the post. There’s just one big problem: I don’t believe there’s any chance the system will work.

Some questions: how does it deal with rear-facing child seats? How does it deal with vehicles where occupants don’t sit in seats facing the direction of travel (like in the back of a Land Rover Defender, or the boot of one of those “7-seat” Peugeot 505 estates)? Or seats in the back of vans? How does it cope with people who set the seat high and have the sunvisor down? How can it detect somebody sleeping or slumping? How can it tell – with the sort of 100 per cent accuracy you’d think was necessary for issuing a summons – that your rear seat passengers don’t routinely sit with a heat-proof blanket over their heads?