it's possible that it can improve, or may in fact worsen the routing computation (as far as time of estimated arrival of arrival is concerned) , depending on the speed assignment of trunk (or primary).
if all trunk within the philippines have the same speed assignment, then routing will definitely worsen. Doesn't make a difference whether it's a Primary Road. Primary can go as slow as 25kmh (on the average at daytime in many poblacion), but can safely be assigned 80-100kph in rural areas. IMHO, trunk or primary assignment of a road will not matter that much as far as routing is concerned, unless we find a practical way to assign different general "speed levels" if trunk or primary enters a poblacion, or if it runs on medium-speed open road, or highway speed. example: Pan-Philippine Highway (also known as Marcos Highway, internationally known as AH26). If this connects many regions from Luzon to Mindanao, then I think it is safe to say that the "entire" AH26 (including all segments) can be safely defined as trunk in OSM (so that when you zoom out the map in most navigation maps, you will see that the philippines is connected north-to-south), because trunk is generally the last to disappear from the navigation map . By careful observation: the same AH26 trunk road road passes MacArthur bridge in Manila, then through the narrow crawling speed of Carriedo Street, and run along the slow-paced Rizal Avenue, all the way to Monumento, where it follows MacArthur Highway (ranging from slow to fast speed), then turns to Dona Remedios Highway passing numerous rural highways all the way to the upper tip of Luzon. Clearly in the Philippines, 'trunk road' cannot be defined by basis of width or speed or quality of road. (it all depends on the budget & time of project completion). my simple impression of a trunk road, is the 'road of choice' when you want to get from one region to another when you are looking at a general map. it acts as a corridor. My opinion maybe biased: Trunk defines the shape of a region, if not the whole philippines (road-wise), but it makes sense to me that my definition is different in rural settings and in urban area. Rural: trunk road (as i earlier stated, (is a major/primary road) that normally crosses the provincial boundary) - of course a little common sense is required. :-) Urban: trunk road may be composed of a system of connected roads (described in one wiki http://en.wikipedia.org/wiki/Major_roads_in_Metro_Manila ). Some may already be considered major roads, some still being negotiated for right-of-way by the government. It was previously assigned either Radial Roads or Circumferential Roads (or sometimes called beltways). Example: by assigning a common highway code C-5 to Tandang Sora, Katipunan, E Rodriguez Jr, and the rest of CP Garcia Ave, they become treated as one road known as C-5 (at least to locals). Although right now, it is slowly turning to a freeway (by defition: fewer exits, U-turns and Stop lights). C-5 does not connect regions, but it connects a lot of major cities (but it is a trunk). Same case with C-4 (EDSA). If the description on wiki is correct, the Radial Roads 9 (which also passes Maharlika Highway AH26), coming from the heart of Manila, goes all the way to La Union via MacArthur Highway (roughly 214km). R-6 which starts from R.Magsaysay, connects to Aurora Blvd, connects to Marcos Highway (Marikina Infanta Road). R-6 connects Manila (NCR), to Rizal, to Laguna, then to Quezon Province (roughly 125km). We don't treat our trunks on per specific road name basis, but per 'system of road' basis. R-1 R-2 R-3 C3- C-4 C-5 although not fully finished are sort of system. there's a zoomed-out image at http://en.wikipedia.org/wiki/Major_roads_in_Metro_Manila if you looked at all the major roads defined (by whoever wrote that wiki) gives meaningful information. it's both functional and beautiful. :-) it says that how NCR is connected, and how it's connected to other regions, to the north, to the south and to the east. if we tag road by function only, it will look ugly (lots of disconnected roads) ;-) I'm one of those pushing for tagging of trunk of some previously defined primary roads, it is not without basis, it's just that the definition of trunk is really loose. (let's use the said wiki for a start + combined with common sense, since some of them are not yet finished) Going back to the connected "provincial roads" of Pan-Philippine Highway (AH26) (with numerous 'local names' along it's length). We cannot be selective with AH26 in treating it as a trunk in it's entirety (same with the gloria project Nautical Highway), regardless of speed, width or road condition. They are all major government projects. The more we inform the public (thru map making) the existence of these long-term road projects, the more funding it gets, the faster they finish. We can just tag that the particular section is under construction, or still unpaved, or whatever :-) As far as routing is concerned, this will be a headache (no doubt). We treat each road section individually. After all, OSM is collecting gps tracks. The actual average speed on particular section can someday be extracted. On Mon, Apr 12, 2010 at 12:05 PM, maning sambale <emmanuel.samb...@gmail.com> wrote: > Pardon my ignorance, what is the benefit of re-classifying the roads > form primary to trunk? I don't mind doing this for my area, but I > need clear benefits before doing this. > > Does this provide better routing? > > On Mon, Apr 12, 2010 at 11:40 AM, Eugene Alvin Villar <sea...@gmail.com> > wrote: >> On Mon, Apr 12, 2010 at 10:47 AM, Jim Morgan <j...@datalude.com> wrote: >>> >>> Eugene Alvin Villar wrote, On Sunday, 11 April, 2010 09:55 PM: >>> > That said, I was actually thinking of upgrading Espana-Quezon Avenue to >>> > trunk. :-) >>> > >>> > What do other people think? >>> >>> My 2 centavos: Trunk roads are inter-city / town. Its also to do with the >>> way people enter/exit the road. So ... NLEX should be a trunk: EDSA should >>> be a primary road. >>> >>> Jim >> >> "the way people enter/exit the road" That sounds like highway=motorway. And >> indeed, NLEX is highway=motorway because it's a high-speed road with limited >> entry/exit points and usually has a toll. >> >> >> _______________________________________________ >> talk-ph mailing list >> talk-ph@openstreetmap.org >> http://lists.openstreetmap.org/listinfo/talk-ph >> >> > > > > -- > cheers, > maning > ------------------------------------------------------ > "Freedom is still the most radical idea of all" -N.Branden > wiki: http://esambale.wikispaces.com/ > blog: http://epsg4253.wordpress.com/ > ------------------------------------------------------ > > _______________________________________________ > talk-ph mailing list > talk-ph@openstreetmap.org > http://lists.openstreetmap.org/listinfo/talk-ph > _______________________________________________ talk-ph mailing list talk-ph@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ph
