Illegal road closure signs

There has been science put up turn off vehicles only next to the Whitford structure barriers but there are no warning signs as you drive down high path so it’s not till you get round the blind bend that you see the actual signs this according to the law is illegal and doesn’t come under guidance of the Traffic Signs Regulations and General Directions (TSRGD) and the Town and Country Planning (Control of Advertisements) Regulations, which require signs to be prescribed, authorized, and correctly displayed.