[Talk-us] Improving coverage of exit numbers and destinations on motorways

Greg Morgan dr.kludge.gm at gmail.com
Wed May 4 08:18:33 UTC 2016


On Tue, May 3, 2016 at 2:46 AM, Jinal Foflia <fofliajinal at gmail.com> wrote:

> There has been a recent push to improve the coverage of exit numbers and
> destination signs on the motorways in the US by the data team at Mapbox.
> Some context here [1][2][3][4]. The primary sources of data were DoT
> documents and Mapillary images.
>
One of the first things that I mapped was exit numbers.  At least that
would provide some clue about the distance you have left or what not.  That
is a great first step but the focus is on urban mapping.  More important
for long distance driving or even navigation are mile markers.  The exit
numbers are tied to the mile markers.  The traffic engineer makes a
decision on an exit number based on the proximity of a mile marker. I have
added part of a press release[2] from Arizona DOT. Milepost/mile maker 346
is referenced.  Milepost/mile markers are far more valuable[1] but are not
rendered and thus have little value to an urban mapper or little reward for
the effort involved.  Also note that the exit numbers/mile makers for a
motorway will reset at state borders.  As I recall I-15 ends around 411 as
you enter Idaho.  Finally, expect gaps in the the exit numbers. Two or more
routes may share a section of the road for awhile until they diverge in
other directions.  Another case, is when the route is split by a city.  In
this case, a route might have run through a city at one time.

The work flow that you mention drive me batty.[0]  At one time there was a
discussion on the list about moving exit_to tags as destination tags on the
ramp.  I moved most of the exit_to tags that I mapped to the ramps.  Here
you are proposing something different by leaving some exit_to tags and
adding destination tags occasionally.  The batty part, is that the original
way I mapped these without exit_to was what I found in Europe. It looks
like Paul has a point because junction:ref is in the wiki page
that Duane cites. I don't know that you can use "does not look like
the x tagging
scheme is very common" or "we will continue to follow the conventional
tagging" when the wiki page has changes as recent as 9/2015.

I don't mind adding these features but there has to be something presented
on the main OSM maps other than another art project.  If you are looking
for mapper participation or encouraging passive users to become mappers,
then there has to be a reward on the main OSM site.  Otherwise, OSM has
developed the most boring video game that shows no lights nor rings any
bells.  It is the cartographers and not the importers that are killing off
mappers!

Regards,
Greg


[0] https://gist.github.com/poornibadrinath/f982a947c6a063ed1a9016a2d3246d4a
Look out for red outer circle for missing destination. Use open in JOSM
button to open the node in JOSM. Orange outer circle represents exit_to tag
and we don't need to add destination tags in the way. Green outer circle
represent that the concern way already has destination tag.

[1] http://www.openstreetmap.org/node/3910143420

[2] Bridge work to close State Route 89 for four hours late Friday
Those traveling between Prescott and I-40 should consider alternate routes

PHOENIX ‒ State Route 89 will close for four hours approximately 13 miles
north of Chino Valley starting at 9 p.m. Friday, May 6, so crews can pour a
concrete bridge deck at Hell Canyon __(milepost 346).__ It’s one of the
final steps in readying a $14.4 million bridge scheduled to open to traffic
in mid-June.
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