Large gateway 30 mph signs mark the start of the speed limit. The first lamp post is 274 metres into the restricted area. There are no repeater signs or road markings indicating the limit. Two of the first five lamp posts are buried in the tree line with the light totally obscured by the branches, so they cannot be seen and do not throw light onto the carriageway when lit. The lamp posts are all drab, dirty dark green, so are inconspicuous. Direction 11 of the Traffic Signs & General Directions, as amended, states that speed limit signs cannot be placed along a road where there is carriageway lighting not more than 183 metres apart, and which is subject to a 30 mph speed limit. A 30 mph limit applies where there are three or more lamps throwing light on the carriageway and placed not more than 183 metres apart. Is the speed limit legal and enforceable please? .