It is a legitimate reason to change the curvature or build a bridge or additional exit in Norway "because it's difficult to drive in".
It's really quite incredible, and combine that with safer cars, and you can really start to eat into traffic fatalities.
That might genuinely be the intention but I'd worry that -- depending on the kind of 'challenge' added to roads -- it might not always work out for the best.
The design is often (intentionally) tricky to navigate. Brick/cobble roads to make driving fast uncomfortable. Planter's narrowing/blocking half the road, resulting in the road frequently being limited to a single lane (often alternating sides) so cars can't simultaneously pass. Frequent 90 degree turns, that sorta thing. It make it impossible to drive fast on these roads.
Note that this is only applied in some "zones", generally this applies to streets with houses, which will then connect up to a 30 km/h max road that is less obstructed and functions as a connecting artery to main roads in the city/town and eventually provincial roads (80 km/h) or highways.
Each classification has different goals, so highways and provincial roads are "vehicles only", cyclists and pedestrians will be on completely separate unconnected paths (usually with several meters of separation from the main road).
Main roads will have both cars and cyclists, but usually separate/designated bike lanes (and sometimes even separated bike paths). Only the 30km/h and woonerf streets really have bikes and cars mixed on the same lane (and will have measures that restrict car speed like I mentioned above).
That may be, but it also made 95% of drivers (those obeying traffic regulations) actually stop for you to cross. Obviously they don't if there's no crossing, and you have to wait ten times as long to cross safely.
Major, expensive stuff like changing the routing or curvature is pretty rare and most likely to happen if the road is reworked anyway.
The two ton vehicle slamming into a pedestrian at medium speeds will probably kill them.
The only way to solve this problem is to lower speeds or remove the car from the road.
A typical European car hitting a pedestrian at 30mph is 80% survivable.
(This road safety video is 14 years old now, and since then some places in the UK have managed to introduce 20mph limits, which are even better.)