frankv:
There seems to have been a spate of these. On a trip to Auckland recently, there were numerous passing lanes on SH1 where the entire lane was coned off for no apparent reason. Certainly no roadworks were in progress.
Also, "road works" where there's nothing being done, and the work is not actually affecting the road (e.g. drainage work). Cones are put out, and a lower speed limit set, for something that does not make the road any less safe than it normally is.
At least it's drainage works. Here in Queensland, we have a 110km/hr motorway reduced to 80km/hr for 5km because there's construction next to the motorway. Not even on it! And for a segment of the 100km/hr motorway, it's reduced to 80km/hr despite there being no discernible road works, even next to the motorway.