lower speed limits on high risk roads
Yip, apparently new motorways with both directions separated, good lighting, well maintained surfaces, good visibility along the route, pretty straight-ish, etc are considered "high risk" and have their speed limits capped to 80 kph (one recent new/upgraded motorway junction comes to mind). Meanwhile I refuse to drive anywhere near 100kph on plenty of roads signposted with 100 kph limits that have no separation between directions, no lighting, surfaces full of potholes and faded lines, poor visbility and/or plenty of sharp curves (including 90-degree curves with 100 kph signs literally only a few meters before the entrance—more common than I think should be the case).
When I see awfully maintained roads signposted at 100 and well maintained roads signposted at 80, I have good cause to question how the speed limits are arrived at. I don't think I can even give the authorities the benefit of the doubt that the speed limits are calculated based on safety...