If there are cones or signs that indicate road work is taking place or has taken place, do you need to slow down? The road works speed limit will be either 40, 60 or 80km/h, depending on the road and the extent of the road works. Minor work that has little or no impact on the lane (e.g. it’s on the shoulder) will result in much less impact than if one lane is closed completely.
However, if there are no speed limit signs, there is no requirement to slow down.
Speed limits variations are only enforced where there are clearly marked signs. If there is no sign, you can continue driving at the appropriate speed limit for that zone.