Ah, that is another discussion. The road type was originally conceived to be used for alleyways in the US. For that it made sense to have another road type instead of a segment attribute. Because there was also interest from the rest of the world, it was then renamed to Narrow Road to better describe what the road type was supposed to represent (as the definition of what an alleyway is seems to differ quite a bit).
Ideally narrow roads would never function as primary streets or minor highways, but sadly we don't live in an ideal world. These kinds of roads don't really shouldn't be part of a drive over a longer distance, so I don't think it hurts to set them as a Narrow Road. But that's just my personal opinion. I don't think it's worth changing these to Narrow Road though, unless you're getting reports of issues on these roads.
By the way: in theory you could have pretty much the same effect as narrow road on a primary or minor highway road by applying the "difficult turn" penalty on each ingoing connection (and not touching the road type). It won't be as visible in the WME though.
Ideally narrow roads would never function as primary streets or minor highways, but sadly we don't live in an ideal world. These kinds of roads don't really shouldn't be part of a drive over a longer distance, so I don't think it hurts to set them as a Narrow Road. But that's just my personal opinion. I don't think it's worth changing these to Narrow Road though, unless you're getting reports of issues on these roads.
By the way: in theory you could have pretty much the same effect as narrow road on a primary or minor highway road by applying the "difficult turn" penalty on each ingoing connection (and not touching the road type). It won't be as visible in the WME though.
Re: New road type - Narrow Street