a banksman is certainly needed when heavy plant is being used. I heard a story of a banksman who got smashed in the back by a JCB bucket. the JCB drivers vision of him was poor as a orange skip cast a background behind the banks man who had a orange hi viz on.
that guy was lucky to be alive.
all safety measures were in place but it all went wrong.
every one has their own risk controls on their rounds but with your if someone tripped on your mat and died you could roll them in the mat 'mafia style', but remember to bend your knees when lifting.

all jokes aside, but most will agree to disagree about your mat. You obviously like to keep tight your H+S procedure, when some will take stupid risks. to a degree your doing your self good, but IMO some is a little out of place, keep building site procedures on a building site. I will never use a mat but there's times that I have tucked hose in gutter or road but then people can park on them.
when you said
As opposed to what actually happens which is that the individual takes more notice of you and what you are doing rather than the floor
remember curiosity killed the cat.
Any way most accidents happen when people are not paying attention, texting while driving or crossing a busy road.
on my side of thing if I don't pay attention to my surrounding I wont know how to assess a situation.
key is to pay attention at what you doing and this country wont have a suing cultre