[Talk-us] Changeset to revert (or defend?)
Frederik Ramm wrote: I think it's quite easy. If NE2 has been there to inspect the individual intersection he has been changing, or at least thoroughly studied aerial imagery or so for this particular intersection, then his idea of how it should be tagged is as legit as someone else's and the issue must be discussed/battled out for each case individually. We don't dispute the facts. (Taking the South Innerbelt example) the freeway is in a shallow valley/cutting, with ramps between the freeway and its frontage roads, and cross streets intersecting the frontage roads and passing over the freeway. The only dispute is about tagging: whether it's appropriate to use layer=-1 for that. Of course, if the freeway is layer=-1, a drainpipe that passes under the freeway would need layer=-2. And a landuse polygon would need layer=-1 only where the freeway is such, and layer=0 on both sides, or otherwise, if continuous, it would be referring to land on a structure above the freeway or land under the other streets. (Personally, I have no issues with a bridge being layer=0 when stuff below it is layer=-1 - we explicitly say that layers are meant to be relative only. Since before I joined (and, in fact, since they were created in 2008), the wiki pages for layer and key:layer have stated that 0 is for the ground level, positive numbers are for bridges, and negative numbers are for tunnels. The bridge within a perfectly flat street should be layer=1 even if the stream is as far below it as the Grand Canyon. As I said, maybe we need a way to mark that this has no consensus (or actively not mark that it has consensus) if there is truly a lot of disagreement with it. At the same time, if people really have been tagging whole thoroughfares with layer=-1 that may in itself be questionable.) Here's an example: http://www.openstreetmap.org/browse/way/17325258/history It looks like this one, at least, was a combination of TIGER screwiness (tiger:cfcc = A33 means Secondary and connecting road, state highways, unseparated, underpassing) and the TIGER import assigning layer=-1 to A33. My personal stance is that layer tags are only necessary when there is ambiguity, but of course I won't remove existing ones where correctly applied. A single bridge is obviously above an intersecting non-bridged way, assuming correct tagging, and we don't need layer=1 on the bridge to make that clear. This of course has no bearing on the current dispute, except in that doing this would have prevented any problems :) ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Changeset to revert (or defend?)
*The recent bot elimination of duplicate nodes. There's been a bit of complaining but no action on reverting it. That's because it was clearly a lost cause - between the validator suggesting that blind mass fixing was the right thing to do, as well as the Heroes VS Villains contest which was ongoing at the time.Add cumulative edits, and reverting the Duplicate Node bots becomes worthless. It's simpler to just waste the time undoing the de-duped node vandalism each time when necessary. ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Changeset to revert (or defend?)
I totally disagree. When surveying, I look at the reality of the elevation of the bridge compared to all the layer-0 features around it. If it is at the same elevation, the bridge stays at layer 0 and whatever it crosses is tagged as layer=-1. This correctly represents the ground truth. This is very commonly the case with concrete drains/canals. It has the added advantage of not requiring rework when you add a new feature to an area - you simply tag that feature with the correct actual layer and no other features need to be edited. This works only if the section tagged with layer = -1 only includes that which is covered by the bridge. Tagging an entire road which happens to pass under a bridge as layer = -1 does not match what's on the ground. ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Changeset to revert (or defend?)
Hi, Mike N. wrote: This works only if the section tagged with layer = -1 only includes that which is covered by the bridge. Tagging an entire road which happens to pass under a bridge as layer = -1 does not match what's on the ground. Correct. We have confounded many old-style GIS people with our layers, where we simply cut up a layer=0 road in the middle and mark a little bit layer=1 or so. What they expect and we don't have is something like a ramp that starts at layer=0 at one end and ends at layer=1 at the other ;) we may yet have to introduce this at some point if we want to correctly map all lanes in multi-storey car parks. Bye Frederik ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Changeset to revert (or defend
So, the real argument here is what is a bridge and what is a tunnel? Many people considered depressed highways to be tunnels rather than the roads over them to be bridges. I saw USGS topos mentioned earlier. Not all manmade cuts are reflected in topo lines. Manmade cuts that are structures are not considered bare earth and are left out. But then you get to the weird idea of are the sides of the depressed highway vertical concrete or sloped ground? and other such criteria. --Brett Brett Lord-Castillo Information Systems Designer/GIS Programmer St. Louis County Police Office of Emergency Management 14847 Ladue Bluffs Crossing Drive Chesterfield, MO 63017 Office: 314-628-5400 Fax: 314-628-5508 Direct: 314-628-5407 -Original Message- Date: Tue, 25 May 2010 03:02:19 -0400 From: Nathan Edgars II nerou...@gmail.com Subject: [Talk-us] Changeset to revert (or defend?) To: talk-us@openstreetmap.org Message-ID: aanlktilxddg8qrs15dualkfomz1yuipuer3svpwcx...@mail.gmail.com Content-Type: text/plain; charset=ISO-8859-1 Frederik Ramm wrote: I think it's quite easy. If NE2 has been there to inspect the individual intersection he has been changing, or at least thoroughly studied aerial imagery or so for this particular intersection, then his idea of how it should be tagged is as legit as someone else's and the issue must be discussed/battled out for each case individually. We don't dispute the facts. (Taking the South Innerbelt example) the freeway is in a shallow valley/cutting, with ramps between the freeway and its frontage roads, and cross streets intersecting the frontage roads and passing over the freeway. The only dispute is about tagging: whether it's appropriate to use layer=-1 for that. Of course, if the freeway is layer=-1, a drainpipe that passes under the freeway would need layer=-2. And a landuse polygon would need layer=-1 only where the freeway is such, and layer=0 on both sides, or otherwise, if continuous, it would be referring to land on a structure above the freeway or land under the other streets. (Personally, I have no issues with a bridge being layer=0 when stuff below it is layer=-1 - we explicitly say that layers are meant to be relative only. Since before I joined (and, in fact, since they were created in 2008), the wiki pages for layer and key:layer have stated that 0 is for the ground level, positive numbers are for bridges, and negative numbers are for tunnels. The bridge within a perfectly flat street should be layer=1 even if the stream is as far below it as the Grand Canyon. As I said, maybe we need a way to mark that this has no consensus (or actively not mark that it has consensus) if there is truly a lot of disagreement with it. ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Changeset to revert (or defend
On Tue, 2010-05-25 at 08:33 -0500, Lord-Castillo, Brett wrote: So, the real argument here is what is a bridge and what is a tunnel? Many people considered depressed highways to be tunnels rather than the roads over them to be bridges. I saw USGS topos mentioned earlier. Not all manmade cuts are reflected in topo lines. Manmade cuts that are structures are not considered bare earth and are left out. But then you get to the weird idea of are the sides of the depressed highway vertical concrete or sloped ground? and other such criteria. --Brett What I used to distinguish a bridge from a tunnel is to ask, Is it a span or a pipe? A pipe puts (or leaves) the support structure around the tunnel. A span puts the support structure under the bridge. There will be some places where this becomes ambiguous, but I haven't found any in my area. - Val - ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Changeset to revert (or defend?)
On Tue, May 25, 2010 at 3:02 AM, Nathan Edgars II nerou...@gmail.com wrote: We don't dispute the facts. (Taking the South Innerbelt example) the freeway is in a shallow valley/cutting, with ramps between the freeway and its frontage roads, and cross streets intersecting the frontage roads and passing over the freeway. Those aren't frontage roads. They're city streets which predate the freeway, which have been converted to one-way in places, as a convenience to the ramps. And a couple of the entrances do not come from these parallel city streets (those mistaken for frontage roads) but directly from north-south streets. Also, the whole situation is going to change over the next 10 years as major improvements are made. The only dispute is about tagging: whether it's appropriate to use layer=-1 for that. Of course, if the freeway is layer=-1, a drainpipe that passes under the freeway would need layer=-2. That wouldn't be hard to do, if the drainpipe could be considered verifiable... And a landuse polygon would need layer=-1 only where the freeway is such, and layer=0 on both sides, or otherwise, if continuous, it would be referring to land on a structure above the freeway or land under the other streets. Landuse polygons and the like should NOT have layer tags. They are to be drawn by the renderers BELOW linear features, even if those linear features have negative layer values. Osmarender screws this up, but nobody with the necessary understanding of XSLT and how Osmarender uses it has been willing to fix the problem. -- David Smith a.k.a. Vid the Kid a.k.a. Bír'd'in Does this font make me look fat? ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
[Talk-us] Changeset to revert (or defend?)
I have found the changes in a particular changeset to be rather unhelpful and in fact quite annoying: http://www.openstreetmap.org/browse/changeset/4363590 Belongs to: NE2 Tags: comment = Removing negative layers from ground-level features. created_by = JOSM/1.5 (3081 en) Some examples of the ground-level features that were stripped of their negative layer tags: http://www.openstreetmap.org/browse/way/26497642 A section of 8-Mile Rd in a volleyball interchange in Detroit. This is a 3-level interchange between two major city avenues, where the middle level is at ground level and in fact provides access to properties and side-streets adjacent to the interchange. Setting layer=-1 on the lowest level makes perfect sense. http://www.openstreetmap.org/browse/way/29687558 A section of the Scioto River in downtown Columbus. While technically the ground is the riverbed itself, this river is certainly lower than anything else around. Most bridges that cross it are tagged layer=0 because they are generally not higher than the rest of the streets they carry. http://www.openstreetmap.org/browse/way/29314498 A section of the South Innerbelt, also in downtown Columbus. This freeway is in a trench, easily 20 to 30 feet below the streets. Were it covered, it could legitimately be tagged as a tunnel. (Eventually, portions of it could be.) All three of these examples, and presumably the vast majority of ways in the changeset, have other features crossing over them that are tagged with layer=0. NE2 did not change those to layer=1. As far as I can tell, he didn't even check for their possible existence. I believe this changeset was done simply to satisfy some arbitrary (and not widely-accepted) restriction on use of the layer tag, putting some academic idea of correct tagging over practical realities. Would anyone like to defend these changes? Of those who would defend it, how many are willing to fix the semantic problems they caused, by increasing the layer on all of the affected bridges (and any bridges over them, and so on)? I think reverting the changeset would just be easier. Unfortunately, I'm a Windows user with no easy way to do that. -- David Smith a.k.a. Vid the Kid a.k.a. Bír'd'in Does this font make me look fat? ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
[Talk-us] Changeset to revert (or defend?)
I'll repeat what I told him through the OSM messaging system: First of all, how did you determine that these features were in fact ground-level? Many times when I set layer=-1 on something it's at least a few feet below the surrounding terrain, if not more. That's still ground-level. Look at the contour lines on a topo map; they'll dip down to follow manmade cuts. Negative layers are for tunnels that are underneath ground level (layer 0). Secondly, it is apparent that you didn't check the layer tags of all features (such as bridges) that pass over these ground-level features. Now there are many instances of layer-0 bridges crossing over roads that do not have any layer tags. Sounds like the problem is tagging the bridges as layer=0. A bridge is, by definition, usually above the immediate ground level. If you wish, I can go looking for bridges tagged as layer=0 and change them to layer=1. By the way, the immediate impetus for removing said negative layers was the large number of highways tagged layer=-1 in areas far from any bridges. So you'd have the main street through a town supposedly underneath any intersecting features (rendered as such and logically such in the underlying data). You may have noticed many residential/unclassified highways rendering above these more major layer=-1 roads. This is probably one of the initial reasons for giving bridges positive layers; they're already split from the longer ways. ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Changeset to revert (or defend?)
On Mon, May 24, 2010 at 8:55 PM, Nathan Edgars II nerou...@gmail.com wrote: I'll repeat what I told him through the OSM messaging system: I responded to those arguments already, in that same system. Rather than rapid-fire replying in two places, I'll wait to see what other people say. -- David Smith a.k.a. Vid the Kid a.k.a. Bír'd'in Does this font make me look fat? ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Changeset to revert (or defend?)
i think i have issues with both sides of this argument: as far as putting layer on a river, there's explicit language about that here: http://wiki.openstreetmap.org/wiki/Key:layer as far as Nathan's editing goes, i think Nathan needs to back off a little and be more cooperative when local mappers have different positions from his. this edit first, discuss later stuff is getting old. i'm really, really not happy with his propensity to take advantage of other mappers reluctance to get involved in edit wars, the result is he gets the last word in because we don't want to be *ssh*l*s. richard ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Changeset to revert (or defend?)
Well said. Zeke On Mon, May 24, 2010 at 9:42 PM, Richard Welty rwe...@averillpark.netwrote: i think i have issues with both sides of this argument: as far as putting layer on a river, there's explicit language about that here: http://wiki.openstreetmap.org/wiki/Key:layer as far as Nathan's editing goes, i think Nathan needs to back off a little and be more cooperative when local mappers have different positions from his. this edit first, discuss later stuff is getting old. i'm really, really not happy with his propensity to take advantage of other mappers reluctance to get involved in edit wars, the result is he gets the last word in because we don't want to be *ssh*l*s. richard ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
