[talk-au] 4WD only tags

David Bannon dbannon at internode.on.net
Wed Nov 7 11:37:30 GMT 2012


Hi Li, I still don't see a problem.

Firstly, I am not aware of any publicly visible map that uses the
4wd_Only tag. Maybe I am wrong, can you point me to one ?

But even if there is, and it renderes as you say, then its still OK
really. We'd see a dotted line and "4wd Recommended" appended to the
name. Like the rest of the OSM database, incorrect date entered will
give incorrect results. 

I'd like to see all grade5, grade6, grade7 and grade8 roads rendered as
a single or double dotted line, Some, depending on their highway= tag
may have a coloured fill. The 6, 7 and 8 have text appended to the name,
5 does not.

In your example, grade6 will have "4wd Recommended) appended but we know
its also got 4wd_Only=yes set. Well thats wrong but its wrong because
the wrong tags have been stored in the database. If someone spots it,
maybe they will fix it and all will be good. Even if it does not get
fixed, people will still be alerted to the fact that it might be a road
needing thinking about. Thats better that what we have now were the
mainstream renderers ignore 4wd_only and we don't have a tracktype
higher than grade5.

David  



On Wed, 2012-11-07 at 21:49 +1100, Li Xia wrote:
> Hi David,
> 
> Here is an example of why the grading combined with 4WD_only tags may not work in 

> conjunction in rendering. let's say all 4WD tracks are rendered using dotted lines 

> (very common on raster maps and widely adopted). What happens when it already 

> 4wd_only=yes but it's also tagged as grade 6? Which tag should take priority?
> 
> Isn't 4wd_only=yes and 4WD recommended some what contradicting?
> 
> Li.
> 
> On 07/11/2012, at 8:20 PM, David Bannon wrote:
> 
> > Hello Li
> > 
> >> what happens when a track is tagged with 4wd_only=yes and grade=6?
> > 
> > Technically I'd see no issue having both those key combos present. In
> > practice not good in that one must be wrong but that won't upset OSM.
> > 
> > In the mainstream maps, the way should be rendered according to grade6.
> > The renderers already recognise tracktype so its relatively easy to
> > extend to grades 6, 7 and 8. The renderers don't observe 4wd_only and
> > sadly probably won't.  
> > 
> > But other applications will still be free to note one or the other of
> > course. How they cope if they actually observe both and note the
> > conflict I guess is up to the app it self.
> > 
> > David
> > 
> > On Tue, 2012-11-06 at 23:32 +1100, Li Xia wrote:
> >> Hi David,
> >> 
> >> Just scanned your personal page quickly while i had spare time so sorry up front if i missed anything.
> >> 
> >> A quick comment on the proposed grading. According to your proposal of tagging grades 6-8, what happens when a track is tagged with 4wd_only=yes and grade=6?
> >> 
> >> Li.
> >> 
> >> 
> >> On 06/11/2012, at 2:23 PM, David Bannon wrote:
> >> 
> >>> 
> >>> OK Li, you ask and you shall receive !
> >>> 
> >>> Here
> >>> http://wiki.openstreetmap.org/wiki/User:Davo#Draft_4x4_road_proposal
> >>> is my very early draft. You and everyone else is welcome to get stuck
> >>> into it, I am not thin skinned !
> >>> 
> >>> The OSM proposal page says to to be verbose, no one need tell me to be
> >>> verbose ! So if its too long, please indicate what needs removing. And
> >>> obviously, error and omissions ....
> >>> 
> >>> I am quite unhappy that it really ends up undercutting the 4wd_only tag,
> >>> they can coexist but I wonder if they will if this is successful. Its a
> >>> shame really, I like 4wd_only and have used it but as I developed my
> >>> arguments it became clear to me that we need a finer grain and its
> >>> probably easier to add levels to tracktype than it is to 4wd_only. And
> >>> it will be easier to get these levels rendered if we go for tracktype.
> >>> 
> >>> David 
> >>> 
> >>> David
> >>> 
> >>> 
> >>> 
> >>> 
> >>> On Mon, 2012-11-05 at 17:28 +1100, Li Xia wrote:
> >>>> No probs david, and you'll be getting plenty of input from me, watch
> >>>> out ;-)
> >>>> 
> >>>> 
> >>>> A draft would be great. Let me know when it's ready to review.
> >>>> 
> >>>> 
> >>>> Li.
> >>>> 
> >>>> On 05/11/2012, at 9:10 AM, David Bannon wrote:
> >>>> 
> >>>>> 
> >>>>> Thanks Li, I have not put that proposal up yet, waiting on a
> >>>>> response to a related matter. Soon.
> >>>>> 
> >>>>> And when I do, I'll not be wanting just your vote, it will be your
> >>>>> input I will really need !
> >>>>> 
> >>>>> Maybe I should put a draft up on my personal page while we wait ?
> >>>>> 
> >>>>> David
> >>>>> 
> >>>>> 
> >>>>> 
> >>>>> 
> >>>>>       ----- Original Message -----
> >>>>>       From:
> >>>>>       "Li Xia" <lisxia1982 at gmail.com>
> >>>>> 
> >>>>>       To:
> >>>>>       "David Bannon" <dbannon at internode.on.net>
> >>>>>       Cc:
> >>>>>       "OSM Australian Talk List" <talk-au at openstreetmap.org>
> >>>>>       Sent:
> >>>>>       Sun, 4 Nov 2012 20:37:52 +1100
> >>>>>       Subject:
> >>>>>       Re: 4WD only tags
> >>>>> 
> >>>>> 
> >>>>>       Hi David, although my opinion is that most render's try to
> >>>>>       simplify the the stylesheet so the map for ease of
> >>>>>       comprehension and would not make use of these additional
> >>>>>       attributes, I see your point and agree that it's useful data
> >>>>>       to have. Since my company focuses on 4WD maps and
> >>>>>       navigation, we will certainly take full advantage of this.
> >>>>> 
> >>>>> 
> >>>>>       BTW, do you have the link to the proposal page? Will go and
> >>>>>       cast a vote.
> >>>>> 
> >>>>> 
> >>>>>       Li.
> >>>>> 
> >>>>>       On 04/11/2012, at 2:41 PM, David Bannon wrote:
> >>>>> 
> >>>>> 
> >>>>>               Li, I beg to differ. While I agree that grading of a
> >>>>>               4x4 track is subjective, so is much of the other
> >>>>>               data in the OSM database. Must be that way.
> >>>>> 
> >>>>>               The real issue is how important the data is. As I
> >>>>>               have mentioned, I am concerned that maps are being
> >>>>>               rendered that ignore this data. Routing engines are
> >>>>>               potentially sending people down roads that they, and
> >>>>>               their vehicles are ill suited to. Bad things will
> >>>>>               definitely happen.
> >>>>> 
> >>>>>               The routing people are saying "but these tags don't
> >>>>>               even show on the OSM maps, why should we worry ?". 
> >>>>> 
> >>>>>               And as to subjective, while there will always be
> >>>>>               borderline cases, I don't think it would be too hard
> >>>>>               to divide tracks up into -
> >>>>> 
> >>>>>               * 4x4 recommended - you will might be OK in a
> >>>>>               conventional car or (better still) an SUV but you
> >>>>>               have been warned.
> >>>>> 
> >>>>>               * 4x4 required - you really need a stock 4x4, a real
> >>>>>               one with (eg) low ratio.
> >>>>> 
> >>>>>               * 4x4 extreme - this is for the death or glory boys,
> >>>>>               they need experience and modified vehicles. This is
> >>>>>               a recent addition !
> >>>>> 
> >>>>>               I am pretty sure that if you and I spent a couple of
> >>>>>               weeks having some driving fun, we'd agree on the
> >>>>>               vast majority of the tracks we graded.
> >>>>> 
> >>>>>               David
> >>>>> 
> >>>>> 
> >>>>> 
> >>>>> 
> >>>>>                       ----- Original Message -----
> >>>>>                       From:
> >>>>>                       "Li Xia" <lisxia1982 at gmail.com>
> >>>>> 
> >>>>>                       To:
> >>>>>                       "David Bannon" <dbannon at internode.on.net>
> >>>>>                       Cc:
> >>>>>                       "OSM Australian Talk List"
> >>>>>                       <talk-au at openstreetmap.org>
> >>>>>                       Sent:
> >>>>>                       Sun, 4 Nov 2012 13:08:22 +1100
> >>>>>                       Subject:
> >>>>>                       4WD only tags
> >>>>> 
> >>>>> 
> >>>>>                       Hi David, just my 2 cents on 4WD_only tags.
> >>>>> 
> >>>>>                       By adding a 4x4 recommended tag will add to
> >>>>>                       the complexity because it's kind of
> >>>>>                       subjective as to which roads/tracks are
> >>>>>                       traversable in a 2WD vehicle, therefor
> >>>>>                       adding another option for this key will
> >>>>>                       further complicate the issue. 
> >>>>> 
> >>>>>                       Li.
> >>>>> 
> >>>>> 
> >>>> 
> >>>> 
> >>> 
> >>> 
> >> 
> > 
> > 
> 





More information about the Talk-au mailing list