[Talk-us] Best way to tag mile and interpretive markers?

Paul Johnson baloo at ursamundi.org
Fri Jul 26 23:07:07 UTC 2013


On Jul 23, 2013 8:16 PM, "Greg Morgan" <dr.kludge.gm at gmail.com> wrote:

> They could but they are not.  Another reason not to calculate these is
the the freeway exit numbers are tied to mile makers in the US.  They pick
the closet mile maker to the exit.  The exit numbers don't always match up
to the exact mile marker location.

Or are sometimes radically different.  I 444's exits used to be numbered
something like 93-97D, before the numbers were dropped, leaving a few
unnumbered exits plus exits A-D, until ODOT gave up entirely on numbering
that route's exits.  That route's length could be reasonably expressed in
yards.

>> and all the extra data might not be useful.
>
>
> I noted on a trip to San Diego that the mile markers in Arizona switched
to call boxes in California.  My son and I tried to use keypad mapper to
record all the call box numbers for OSM but could not type them fast enough.
>
> In a large city, a mile marker might not be that useful because there are
exit numbers.  However, if you drive in the wild open middle of the
country, then you can go for 10 or more miles before you see an exit
number.  These are quite useful in that case.
>
> I've also heard that all the Utah DOT engineers live and breath by mile
markers.  They use 'em to look for deadly areas that need to corrected or
other such engineering problems.  I wonder if other states use the markers
for the same purpose.
>
> Just as when I took a trip and logged all the exits between Phoenix and
Flagstaff, I added a couple of refs and exit_to tags on US 60 after a
weekend drive.   So at mile marker 97 you know that you are half way on the
road and the exit_to says power lines.   LOL  There are also a couple of
exit_to makers in Wickenburg too.   I understand that using exit_to is a
poor choice but it renders.  These mile markers are useful on a map because
you can use them as an intuitive calculation of when and where you may need
to fill up the gas tank.
> http://www.openstreetmap.org/?lat=33.962&lon=-112.825&zoom=11&layers=M
>
>
>>
>>
>> I think it's not a problem tagging these as milestones, and there are
other people already doing it around here. If there is a particular marker
stone I'd use additional tags like historic to underline the significance.
You can calculate the length of road segments but maybe they won't
corrispond in every case with the exact position of the signs, and as you
can see the markers as feature on their own they can also be mapped.
>
>
>
> Adding these makers takes some work just like addressing does. The effort
to correct survey mistakes makes it difficult to add these milestones, if
the cartographers don't show 'em.
>
> As noted above, even though you have a whole mile to type in the marker
with something like Keypad Mapper2, I don't know that the GPS on the phone
will make the maker location any more accurate than calculating them.
Since these markers reset on each road and at state boundaries for
something like I15, you'd have to have a GPS point that is created while
you are stopped at a marker to accurately calculate the rest of  the
markers from a known location.  For example, I15 starts at 1 in south Utah
and finishes either at 401 or 411 at the Idaho border.
>
> Regards,
> Greg
>
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