[Tagging] Clarification unclassified vs residential

[Jarek Piórkowski]

On Wed, 27 Feb 2019 at 13:52, Paul Johnson <baloo at ursamundi.org> wrote:
> On Wed, Feb 27, 2019, 12:41 Jarek Piórkowski <jarek at piorkowski.ca> wrote:
>> On Wed, 27 Feb 2019 at 13:32, Paul Johnson <baloo at ursamundi.org> wrote:
>> > On Wed, Feb 27, 2019, 11:25 Fernando Trebien <fernando.trebien at gmail.com> wrote:
>> >> I never thought that emergency access would determine highway
>> >> classification. It seems like a secondary use of the way, not its main
>> >> use/purpose.
>> >
>> > motor_vehicle=no would exclude most emergency vehicles.
>>
>> I thought we were saying access tags like motor_vehicle are legal
>> access, not physical access. I do not expect emergency vehicles to be
>> excluded by legal access tags.
>
> access=no by itself is absolute.  I would expect most roads in the DMZ between the Koreas (that aren't too overgrown and weathered away from a half century of being disused) would be an extreme example.  You're not getting even fire or paramedic vehicles down it, period, it's not happening.

Thinking back I've used access=no like this as well ("you can't go on
this bridge, the city closed it because it might fall down"), though
I'm unsure if that's indeed absolute in many of the uses of access=no
in practice. And motor_vehicle=no seems even less likely to be
absolute - unlike in Korean DMZ, most of "no motor vehicles"
regulations are probably not enforced by people with guns.

> emergency=yes is the most common value, it's a modal/class exception.

Right, when explicitly tagged. But I would not tag every pedestrian
way that is wider than 3 m as emergency=yes just because a fire truck
might use it to reach a location in a city centre, and I'd expect the
same to be the case with ways that have motor_vehicle=no (unless
physical properties of the way, or immovable barriers, prevent this).
Like Fernando said: "I never thought that emergency access would
determine highway classification."


--Jarek