Dear Totor,
I only discovered your message in my spam folder yesterday. I was the one
who edited and put all those ref by DPWH on primary roads (doing some
tests, checking for patterns all over PH)
The reason for the delay in reply is that I need to type an extensive
guidelines on trunk-editing (for osm learners) which is confusing to many.
I am fact-checking existing examples in OSM PH, where I myself broke the
recommended road classifications of DPWH many times.
It's better to explain by-example (and reason why), so that other mappers
reading this can benefit from discussion (links: to follow later)
My edits in Cebu Proper:
Route 8 (camino real) which is classified as primary by DPWH (equivalent to
trunk road) in OSM. I initially followed faithfully the DPWH's route -
which in "many times" proven as outdated. Is the current trunk route shape
still valid? Reroute if necessary, but leave the DPWH ref value intact.
Route 840 coastal road (by-pass or diversion road), which also appeared as
trunk on OSM. I initially decided to downgrade this to primary route -
prior to testing and consultations with local mappers (see my personal
guidelines below - second rule)
As for the 2 bridges that goes to the airport (they also run in parallel) -
having the same function (applying my second rule). I did not touch Marcelo
Fernan route (check edit history) :-) I just saw the original route on
DPWH's database, the Marcelo Fernan isn't even on DPWH (probably a city or
provincial road - national road?) - didn't noticed coz I was in a hurry
that time (forgot to open a discussion for consultation). If you feel
Marcelo Fernan qualifies more as a trunk than the other bridge (considering
the guidelines below), then by all means, tag it correctly as you see it on
the ground.
Anyways, better this way... "somebody breaks something" (as I always break
something, hehe), we have more people interested in reading and learning,
how we will solve this :-)
Please see my personal notes below.
Cheers,
Rally
I use the following guidelines (rules) in my head in editing primary and
arterial roads.
This is not yet an extensive list and I wish we can get more ideas from
others.
*First Rule*: Don't follow DPWH recommended routes, they are just guide.
They're outdated in so many areas (I will show many examples in various
areas that doesn't make sense).
*Second Rule*: No two (or more) trunk should run in parallel routes (having
same regional function).
The typical case of (old) Camino Real vs. (new) Diversion/By-Pass Road --
choosing which one will be the designated provincial or regional trunk road
in OSM map? (forget DPWH). But you should only have one trunk crossing a
town or typical city, by looking at it in the regional or provincial
perspective.
*Clue: look at the intention of DPWH (regional planning). Have they widened
the old primary routes (to maintain primary status)? But if the Diversion
Road is being redesigned with more capacity: twice as wide, twice as fast
as the old route, and is actually used by regional motorists, then the
answer is obvious. *
This is tricky in example Lubao By-Pass Road (Pampanga). Maybe because said
By-pass road is not a National Road? same case with Marcelo Fernan Bridge
(not on DPWH)
If we notice, DPWH uses the same concept: they rarely have two 'primary'
running in parallel.
eg. In the case of NCR, even if Alabang-Zapote is far from Sucat Road, they
tag Sucat Road as primary, Alabang-Zapote as secondary (even if the latter
is allegedly part of the old Daang Maharlika). My theory is that DPWH treat
these two road serving the same function (in the future): linking SLEX (E2)
to CAVITEX (E3/E4). But I tend to disagree and will recommend
Alabang-Zapote be tagged as Trunk, because I believe Daang Hari will become
trunk someday, then it will violate my *Third Rule.*
*Third Rule:*Trunk should not terminate in the middle of somewhere. It
should typically terminate on:
(1) another trunk road
(2) expressway
(3) major port/gateway: international airport or seaport, or a major ro-ro
terminal (SRNH)
(4) self-contained major city, eg. provincial capital
(5) circumferential provincial roads that ends on itself (in some islands)
examples:
- trunk road stopping at Tabuk, Kalinga (because it's the capital)
- decision to extend Quezon Ave (N170) from Mabuhay Rotonda to the nearest
trunk, which is AH26 (N120 Roxas Blvd) via N150(Padre Burgos) instead of
via N170 (Taft Ave back to EDSA); because routing to Taft Ave will break
the Second Rule (running parallel trunks with N120(Roxas Blvd) and
N145(South Super) which are also both located in Manila, all going in the
same direction to EDSA.
*Fourth Rule:* Test if it is really "THE" trunk road.
This is a tricky balancing act, considering its function, the original govt
design and how ALL (INCLUSIVE) motorists actual use them. (I had
contradicted/reverted my own edits so many times, after the quest
