I’ve actually figured it’s better and (professionally) safer for me to just pony up and buy the school a bunch of free standing ‘no parking’ signs, and just donate them!!!
I wouldn’t waste your money, they had the signs and the plastic bollards with plastic chain outside our local primary school. They had to be binned as they had been damaged by cars, I would like for there to be a punchline here but the driving standards and entitlement are such that this isn’t the case.
I challenged a mother one morning when her front wheel was on the base of the sign and she told me “it’s OK, I wont be long”, no amount of pointing to the signs and explaining improved things so I left before I smashed her car to bits in front of a few hundred kids and parents doing the morning school run.