Before I start, this is not a criticism of people parking as i don't really know too much about it.
So, where can people who require a blue badge, legally park? For example, are they allowed to park on double yellow lines, in bus stops or in loading only areas?, all of these I see regularly in Sheffield, even though there are many disabled bays around.
I'm sure most blue badge holders park where they should but there's always some that think they can park wherever they like because they have a blue badge.