Yeah inner London then that makes sense, and a town centre pedestrian zone that makes sense, honestly, as a cyclist/pedestrian, it is quite rare to get the horrendous car fume smell of 25 years ago in modern traffic, so even then that one car not relatively that bad compared to 90% that perhaps even, as Ford boasted about, about 20 years ago, the petrol engine car actually cleans the air around it… That is to say probably on that marketing angle meant produced less net soot given it near hepa filtered the air it took in and indeed converted some gasses in the catalytic exhaust… and were just quite efficient, apart from power to weight ratio wastage thing…
I guess if you were to hand a portion of the cash back to the vehicle owners to get a new catalytic and air filter or whatever then that might be quite good… 12.50 a day, a new air inlet filter a month (or two, I guess the cabin filter actually cleans the general atmosphere as well) and a new catalytic every year or two, plus fitting of parts keeping people in jobs, they know your number plate and who you are eh! payback eh!
Personally, I would just charge the rich c@nts in 4×4’s and GT/Luxe cars double or triple the 12.50 rate, and still pay back the air filters/cats to the plebs. Including charging those “holier than thou” EV c@nts!