Those rules on road heights apply to open roads upon which traffic is travelling.
If traffic is using the road then the reference height is surface+4.5m, but if the traffic is stopped (as it is at Waddo by the flashing red lights either side) then you can use the road surface as your reference height.
This is why Waddo has to stop the traffic for a/c movements, otherwise the road traffic would infringe the approach/climbout surfaces.