davipt wrote:What do you mean fallacy? No of course I can't find the exact sentence on the wiki,
Then you shouldn't say the Wiki says so, cause it probably doesn't.
davipt wrote:but isn't it well known that streets do change from unknown to one-way and to two-way, but will never ever be able to learn and switch back from two-way to one-way?
No. I've had a street go from two-way to one-way, simply because I was the only person driving down it, and I always drove in the same direction.
davipt wrote:Also routes will prefer segments manually set to two-way over segments marked as unknown?
Maybe. But if you have local knowledge and know all the streets are two-way, then it's better to set them all to two-way, as that is what they should be. As long as you then take the time to add all the other data - road names, turn restrictions, etc.