[Talk-us] emergency access, no u-turns on interstates & other motorways

[Richard Welty]

this has been on tagging for the last two days, i'm looking for comment 
from a broader
audience. take your best shots...

the context is that i'm working on an emergency services project (some 
of you may have seen
my blog post here:
http://www.averillpark.net/thisendup/index.php?/archives/101-OpenStreetMap-Emergency-Services.html 
)
and there are lots of cases where access=no or access=private is 
commonly used but are not
strictly correct characterizations of the situation. my original request 
was for access=emergency,
which would be used on nodes (e.g., gates that emergency vehicles are 
authorized to pass through
but not normal traffic) and ways (e.g. u-turns on motorways.)

what follows is a very light rewrite of what i just sent to tagging in 
response to
discussion there.

----------------

First, i've learned that when we tag U-turns as access=no or 
access=private, we're
probably doing it wrong, and tagging them as access=emergency is a band 
aid, not
a fix. we should probably allow it as a band aid, but see about 
switching to a
different approach.

specifically, no U-turn is the common signage in many jurisdictions, and 
that's a
turn restriction, not an access restriction. in  a perfect world, that's 
how we'd have
tagged all of these. an access restriction is appropriate if there are 
signs saying
"emergency vehicles only" or something similar.

i looked up the actual language in the NYS vehicle code (Article 23, 
section 1104):

    (b) The driver of an authorized emergency vehicle may:
    ...
    4.  Disregard  regulations governing directions of movement or turning
        in specified directions.

this has nothing to do with ignoring access=no or access=private, and 
everything
to do with ignoring turn restrictions and oneway indications when 
responding
to an emergency.

so my suggestion is:

access=emergency

for situations where posted signs are present, and as a temporary expedient
for "no u-turns" that are currently marked private or no. the page 
documenting
access=emergency should recommend moving to an "only straight on" turn
restriction in the long term (no U turn is obvious but the typical 
configuration
of the turnarounds makes it hard or impossible to use.)

i also recommend that access=emergency tags be deployed in association with
source:access tags that give the authority, e.g.

source:access=NYS VAT Article 23 Section 1104 (b) 4.

source:access=posted sign

richard