[Tagging] access=emergency revisited

[Richard Welty]

On 11/21/12 7:32 PM, Anthony wrote:
> On Wed, Nov 21, 2012 at 5:42 PM, Richard Welty <rwelty at averillpark.net>wrote:
>
>> On 11/21/12 4:00 PM, Anthony wrote:
>>
>>> If emergency responders are exempt from access restrictions (which they
>>> are
>>> in every jurisdiction I've ever read the law on), then the access tags are
>>> of limited usefulness regardless.
>>>
>> they are valuable as a way of storing verified information.
>
> By tagging a road the same way whether it says "emergency vehicles only" or
> "do not enter", you don't gain information, you lose it.
>
huh?

a conventional driver won't enter the road either way.

a routing engine may need to make the distinction, and it's distinction 
needs to be
made on the basis of local statute and/or policy. you've offered up a 
case based on
"every jurisdiction i know of", which is anecdotal evidence at best. i'm 
expecting to
encounter considerable variation based on jurisdiction as i build this 
project out.
there will likely need to be local policy files for unique cases, but 
the fundamental
question is are we going to reflect actual law/policy on the turnarounds 
or the
the state of the signs.

we're losing information either way, the question is what kind of 
information are
we prepared to lose.

richard