I recently a friend in Bath move house only to subsequently be contacted by letter that I had been fined £129 twice i.e. once for the Saturday night and once for the following day.
Apparently, it's due to the city being a 'Clean Air Zone', something that I had never heard of before.
After appealing on those grounds, I managed to get the fines reduced to just the £9 charges on each day - but it begs the question as to how the motorist finds out about such things (and for all I know there may be other types of zones around) in advance of leaving one's own vicinity. Is there a 'collector' site of all types of zones available anywhere?