> This seems like a personal anecdote and not a software feature.
It might be.
> How does one even define that?
One example would be a road that is very narrow, but not one-way. Basically so narrow that only one car can drive there. Where I live, there are many such roads on the country side. They tend to be used as shortcuts so that one doesn't need to take the main roads (shorter total distance). But they are dangerous in the sense that you have to pay much more attention when driving there. Google just tends to prefer those for some reason.
> You're saying that there are special roads that Apple knows not to travel bug Google does?
No. I am saying that the directions suggested by Apple Maps tend to avoid those roads, while Google Maps oftentimes doesn't even display an alternative.
> That seems odd, since the real world doesn't really mark its roads like that.
Ever driven on a gravel road slowly to not get stones hitting your car? I am sure there is a way to index the road quality and that this is even easy based on satellite and air photo data.