[Talk-GB] Tagging maxwidth "Except for access"

[Robert Whittaker (OSM)]

On 31 May 2012 11:23, Colin Smale <colin.smale at xs4all.nl> wrote:
> Maybe I am just having a "blond moment" but I can't see any way of capturing
> access restrictions "except for access". Loads of country roads are
> signposted as "max width 6'6" - except for access" which implies a wider
> vehicle will fit (just). There are other restrictions which are sometimes
> qualified in this way, like "No HGVs except for access" but when they
> specify a class of vehicle then the tagging is obvious - in this case
> "hgv=destination". But this can't be done simply with maxwidth (and
> maxweight, maxheight).
>
> As I can't see any direction on the wiki I thought I would let up a balloon
> here to see if anyone has come up with a tagging solution for this (in my
> experience) typically British phenomenon.

Where I've come across these "exceptions" to the restrictions, I've
used something like:

maxweight:exception = loading;permit_holders

The other sensible way of doing it that I can think of would be to
have a separate key for each class of user taht has the exception. So
something like

maxweight = 7.5 T
maxweight:loading = no
maxweight:permit_holders = no

The first approach better reflects the reality of the signs -- it's
not a case of multiple restrictions; it's one restriction, with a list
of exceptions. The second second approach is more flexible though, and
is more consistent with the documented maxspeed:hgv tag. However, I
think the second method is slightly ugly, in that we have to have a
"no" value to remove the original maxweight.

With either method, it would be good to document a list of simple
words to express common exceptions.

Neither approach had been particularly heavily used though, as far as
I can see from taginfo.

Robert.

-- 
Robert Whittaker