[OSM-talk-ie] mapping roads

Andrew McCarthy me at andrewmccarthy.ie
Sat Mar 15 22:10:12 UTC 2014


On Fri, Mar 14, 2014 at 06:27:13PM +0000, da fo43 wrote:
> 1.       Map L roads 1000 to 4999 (Local Primary) as ‘Tertiary’ and all other public roads as ‘Unclassified’ or ‘Residential’.
>  I know people have a lot of differing views on this and will admit that
>  some local primary roads seem to have less importance than Local 
> Secondary and Local Tertiary roads but really I think it’s better to go 
> with what is designated rather than making judgement calls. On some 
> parts of the map all roads are being set to ‘Tertiary’ so really I don’t
>  think the current system works. All other roads are mapped as per 
> designation so I personally don’t see why this should be any different.

Setting all roads to tertiary without thinking is clearly no use.

However, I don't think using the local subclassification (primary/
secondary/tertiary) blindly is any use either. Unlike the national and
regional routes which are actively updated and revised, local
classifications aren't. Many of them make no sense at all.

Some examples:

- Local primaries cut in half by new motorways are still classed as
  local primary, even though they're now a little-used dead end to two

  This junction, for instance:
  It would be odd to have all of L3930 marked as tertiary while L39307
  and L39306 are unclassified, especially since L39307 is now the "main"

- Some roads change for no obvious reason:
  The L2133 becomes the L6139 and then the L2133 again. From a driver's
  point of view it's a single continuous road. Having an isolated bit of
  unclassified in the middle makes no sense.

- There are large areas in which there are no local primary roads.
  However, when you drive them there are clearly "main" roads (wide with
  lane markings) and boreens. Marking them all as equal in OSM is no use
  to users of the map (especially larger vehicles), and no help to
  routing software such as sat navs.

  Around Narraghmore and Calverstown:
  with everything marked as unclassified there's no indication which
  roads to take.

  This is the L8016:
  and this is the L8011:
  Both local secondary, but clearly nothing like the same type of road.

- Roads that cross county boundaries can change classification. Changing
  from tertiary to unclassified just because you crossed the county
  boundary will look wrong.

  For example:
  South of the county border is Laois Local primary L3976, north of
  the border it's Kildare Local secondary L8065. The L8065 is actually a
  better, and busier road. It makes no sense not to mark it tertiary.

The whole local subclassifications are a mess.

>  2.       Labeling roads L1000-9999 with spaces.
>  I see on some parts of the map that roads are being labelled with a 
> space ‘L 1234’ instead of ‘L1234’. I would be in favour of sticking to 
> one standard, and going with the majority in not using a space.

Yes, no spaces.

>  3.       Labeling roads over L9999.
>  I propose the labeling roads listed as L12341 as L1234-1 as 
> this makes it easier to read and work out which branch of 
> primary/secondary road it belongs to. I guess this might not suit 
> everyone.

Refs in the form L1234-1 are used, behind the scenes, by councils to
indicate subsections of the local road L1234. Take a look at the
schedules on the Wiki to see what I mean:
All signage is in the form L12341, too.

> 4.       Non public roads to be displayed as ‘Service’ or ‘Track’ only.
>  It’s not always obvious if some roads are private (especially some 
> housing estates) but where it is known for certain they are private then
>  I would be in favour of using a ‘service’ road rather than 
> ‘residential’ or ‘unclassified’. 

For non-public laneways, driveways, etc, they should be service. For
housing estates, though, I'd leave them residential, that's what it's



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