[Tagging] barrier enforcing maxwidth

[Carl von Einem]

Martin Koppenhoefer wrote on 08.09.15 11:53:
>
>> Am 08.09.2015 um 11:12 schrieb Carl von Einem <carl at einem.net>:
>>
>> barrier=guard_rail
>> maxwidth=2.2
>> traffic_sign=maxwidth
>
> traffic_sign is a tag used to tag actual traffic signs
> at their position, it doesn't look right together with
> a linear barrier like a guard rail which very likely
> isn't a traffic sign itself along all its way

Did I write it must be a part of a way? I think both (node or way) work, 
but it should definitely be on the way: as a node on the actual position 
of the traffic sign it's maybe nice as a landmark but completely useless 
for routing software.

Also the traffic_sign tag indicates (to other mappers...) that the 
maxwidth value isn't just estimated. I definitely see the traffic sign: 
https://goo.gl/maps/8KUw7

According to <https://wiki.openstreetmap.org/wiki/Key:traffic_sign> the 
tag traffic_sign can actually be used on a way: "The tag is not meant to 
mark the actual position of the sign in this case, but the affected way 
or area instead."