[talk-ch] Pls, don't delete sidewalks, visual impaired people might use them

marc marc marc_marc_irc at hotmail.com
Thu Aug 24 23:12:56 CEST 2017

Le 24. 08. 17 à 21:56, Marc Gemis a écrit :
> when you can better tag a sidewalk with a separate line, why not ?
If a see a sidewalk and a street (2 way separated from each other with a 
space between both), I tag them as such.

if I see a street with 2 lanes, I tag one way, lane is a characteristic 
of the path like its surface or its width.

I see one way with a lane for car and sidewalk for pedestrian, I tag one 
way highway=residential + sidewalk=both

No one agrees to divide a two-lanes road into two ways because it breaks 
the routing despite geographic precision would be better.
I don't understand why we sometimes do the opposite with sidewalk.

Blind user have no problem to find the limit between a raised sidewalk 
and a street. Create a disconnected sidewalk where it is not the case 
has a low utility due to the fact that a gps have a low accuracy.
But break the routing could make a blind user to cross where you can't.
In the example of the list talk, depending on the algorithm used, the 
user had the choice to cross anywhere without knowing whether it is 
possible or not or walk 100m and walk on the street next to the 
artificially disconnected sidewalk. The 2 are worse than 5m inaccuracy.

Therefore we must do things in a good order :
1) have a tag or relation with a meaning "This sidewalk is separated for 
  geographical precision, but for routing, it is permanently connected 
to the road".
2) Have at least one routing algorithm that can use it.
3) It is only afterwards that one can draw the sidewalks separately 
without sending the people into a dangerous situation.

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