On Wed, 7 Aug 2019 at 04:40, Michael Tsang <[email protected]> wrote:
> > The ability of through traffic passing a road does not depend on the > classification. As long as it is the shortest / widest / fastest path > connecting major roads, it will have through traffic even the driving > experience > is the same as driving into a cul-de-sac in a neighbourhood. Therefore we > don't need to distinguish them in the tagging. The residential / > unclassified > difference should be reflected in the driving experience (you expect > houses and > residents on residential road which you should be careful not to disturb > them, > but not on an unclassified road). > I can see your argument, but I disagree with it. Perhaps it best describes the situation in Hong Kong, although I suspect not. I definitely disagree with it when applied to the UK. The UK has four official, government-assigned classifications of through roads: primary (A roads), secondary (B roads), tertiary (C roads) and quaternary (U roads, where U unfortunately stands for "unclassified" which some mappers misinterpret as meaning "uncategorized"). There are also motorways (level 0 in the 1-4 hierarchy) and trunk roads (level 0.5 in the 1-4 hierarchy). Standard carto gives secondary, and higher, roads their own colours and renders tertiary roads wider than residential roads. This allows people to use that most primitive of routeing algorithms called "looking at the map." Your scheme would break this whenever such a road passes through a town. In my part of the world there are many "ribbon" villages along primary and secondary roads. Perhaps no more than a dozen houses, possibly only one one side of the road. By your logic the road ceases to be a primary road and becomes a residential road. A long stretch of red/pink road with a bleached bit where the village is. Here, for example, is the junction of a secondary road (the B4548 which consists of Gwbert Road and Aberystwyth Road) with a tertiary road (North Road). https://www.openstreetmap.org/?mlat=52.0871&mlon=-4.6543#map=16/52.0871/-4.6543 And here is an image of that junction: https://goo.gl/maps/M6XnHj8VKfRdG5Ad7 You can see from the signage that it's a through road (residential roads don't have such signage). You can also see from the houses in the background that it is a residential area. In fact, those houses are about as densely packed as anywhere in Cardigan. many of the residential roads are less densely packed. To continue the example, during road works on North Road, traffic is diverted along Napier Street (residential), Napier Gardens (residential), Maes-yr-Haf (residential), Rhos-y-Dre (residential), Maes-Henffordd (residential) and Feidr Henffordd (residential) to rejoin Aberystwyth Road. It's possible for through traffic to take that longer route but it normally doesn't. And it's even less likely after the speed limit along much of that diversion was dropped from 30 MPH to 20 MPH a couple of years ago. Just to show that a residential road like Napier Gardens has a lower housing density than Aberystwyth Road, https://goo.gl/maps/5fGPgoiXQH7A8wkP7 I can see the argument that Aberystwyth road is also residential and therefore drivers ought to be more careful. But that is indicated by mapping houses along it (or at least mapping it as a residential area). Speed limits also indicate that drivers should be more careful. As always, there are compromises to be made. But in much of the UK (and probably much of elsewhere) mapping a road that is both a tertiary (or higher) route and which also has houses along it as residential is not the best way of dealing with the problem. All in my opinion, of course. -- Paul
_______________________________________________ Tagging mailing list [email protected] https://lists.openstreetmap.org/listinfo/tagging
