[Tagging] Formally informal sidewalks

[marc marc]

Le 15. 07. 17 à 19:06, Nick Bolten a écrit :
>  > marc marc wrote:
>  > For wheelchair routing.
>> If all crossing have a lower kerb, it is maybe enough to add
>> sidewalk:both:wheelchair=yes to the street.
> wheelchair=yes should be used sparingly,
you are right, i use it only when there is no barrier, when all crossing 
are lowered, enough width , good surface, no incline....
In case of doubt, I do not put this tag.

>>> easier to add characteristics for wheelchair routing to them.
>> you can add those tag to the street as documented here
>  > https://wiki.openstreetmap.org/wiki/Wheelchair_routing#Sidewalks
>  > for example I use the following tag on the street :
>  > sidewalk=right
> Yes, but that's a fairly unnatural way to describe a pedestrian way: 
no, it isn't a pedestrian way, it is a street with sidewalk, it is not 
the same for routing.

> leads to spatial inaccuracy
well... every way is a spatial inaccuracy because we use a way in stead 
of an area.. and in real live and routing, it doesn't care, everything 
work fine except that the map doesn't show the real width.
See area:highway proposed features pending for a few years :-)

> it becomes a real maintainability nightmare.

Or not, the street and the sidewalk do not change often here (> 10 years),
the sidewalk is often the same type/surface/kerb ... for the whole street.
But if you cut the sidewalk away off the street, routing problem will 
often occur.
Before advising people to describe as separate path when this is not the 
casethe routing must first understand that our 2 way are a sidewalk 
connected to a street.If not, you break the routing and the only 
advantage seems to move sidewalk 3m away.

>  > Guidelines for roads is very easy: split a road in 2 when you can NOT
>> switch from one to the other (for example a road with a island). and
>> create connection where you can switch. But do NOT cut a road into 2 if
>> you switch everywhere from one to the other (for example a street with 2
>> lanes must be keep as one street, not 2).
>> Just do the same with the sidewalk as if the sidewalk was a lane
>> reserved for pedestrians. I never see a problem with that.
> Ah, but it's almost never valid to switch from a sidewalk 'lane' to a 
> street 'lane', 
Read me again, I did not say you can walk on the road if a sidewalk exist.
I stated the rule used to know when a road must be single or splited.
By keeping this rule for sidewalks, we avoid a lot of routing problem. 
Routing will be able to choose where to cross the street or what todo 
when sidewalk stops because tags show that the sidewalk is connected to 
the street without obstruction between them.

Regards,
Marc