[Tagging] Clarification unclassified vs residential

[Fernando Trebien]

On Wed, Feb 27, 2019 at 4:58 PM Mateusz Konieczny
<matkoniecz at tutanota.com> wrote:
>
> Feb 27, 2019, 7:31 PM by baloo at ursamundi.org:
>
> motor_vehicle=no would exclude most emergency vehicles.
>
> No, it would not. motor_vehicle=no is a legal limitation.

Currently, it actually would because emergency=* is nested under
motor_vehicle=* in the access tags hierarchy. [1] So to express that
motor vehicles (cars, trucks, etc.) are forbidden but emergency
vehicles are not, both motor_vehicle=no + emergency=yes are required.
The same would happen if access=no was used instead of
motor_vehicle=no.

I agree that typically emergency vehicles are allowed essentially
everywhere due to the nature of their emergency work, so maybe the
hierarchy should be changed by moving emergency=* to be a sibling, not
a child of motor_vehicle=*, or perhaps even a sibling of vehicle=*
since emergency work in certain areas might be provided using human or
animal-powered modes of transport.

> And if anything, presence of legal motor_vehicle=no may hint
> that motor vehicles would be able to pass it, so it was made illegal.

Usually yes. But when used on highway=path, I wouldn't be so sure. Or
if one for whatever reason redundantly puts motor_vehicle=no on, say,
a sidewalk, I wouldn't be so sure either.

> So I would consider motor_vehicle=no as making it more, not less
> likely that road is passable.
>
> To exclude emergency vehicles one should tag physical, not legal
> barriers.

Agreed again, though it is still possible that even emergency vehicles
are not legally allowed in certain places, such as military and/or
conflict zones.

[1] https://wiki.openstreetmap.org/wiki/Key:access#Land-based_transportation

-- 
Fernando Trebien