Addition of a road type: Dangerous or Unsafe road
It is suggested to add one more road type: Dangerous or Unsafe road. This type will be used for example when it is a very steep or winding or bumpy road, or a road on the edge of an abyss.
The time it takes to pass the road in such cases is not the only parameter that counts.
It is suggested that the "penalty" for passing such a road will be proportional to its length. For example 1 minute for every 100m.
דויד ק commented
Rank the different road segments according to safety standards and accidents reports. For example, a road with a hard, stone separator between lanes and wide margins would score higher on safety than bi-direction road of two lanes only, with no separation between the lanes and thinner to no margins. Given a route, a safety score will be given to the driver so he may pick his road by safety rather than time.
Daniel Weishut commented
Excellent idea! Though I'm a good driver, I have found myself occasionally in situations in which I probably would have not taken a certain road, had I known in advance it is that dangerous. This happened to me both with a very steep road and with a curving road with on one side a valley.
Alternately, perhaps segments could be marked as "difficult" the way turns can be marked now. Then, the user's decision on whether to be offered difficult routes could apply to difficult segments as well as turns.