[OSM-talk-ie] FYI: N Route re-designations as Motorways

[Dermot McNally]

Hi Richard,

As the person who ratagged the last batch of roads to be redesignated,
I'll offer some comments inline:

2009/7/15 Richard Cantwell <manaboutcouch at gmail.com>:

> Just a quick heads-up, if you havent heard elsewhere, the Motorway
> re-designation scheme is coming into effect on August 28th.  Details here:
> http://www.irishtimes.com/newspaper/ireland/2009/0714/1224250638091.html

That's a dreadful article from start to finish, and that includes the
standard of English in it. A few points about the contents:

The M3: This was planned from the start to be motorway and is being
built under a motorway order. There _is_ a redesignation planned for
an existing piece of N3 (north of the northbound Clonee exit) which is
to become M3, but they can't physically perform this redesignation
until the southernmost part of the new M3 is complete (including link
roads) as far north as Pace.

As Tom points out, the bulk of the roads to be affected are currently
under construction. While not being constructed under motorway orders,
those schemes that are far enough advanced to have signage erected and
lines painted have already been constructed as motorways in waiting,
and our OSM tagging reflects this (witness the long stripey blue lines
running alongside the N7 and N9). Each such scheme that opens will
simply be retagged from construction to real, a process which
generally takes 5 minutes with JOSM. Traditionally I've tended to be
the person sad enough to do that retagging once the opening ceremony
has completed.

> It would be demonstrative of the power of crowdsourced data if we could
> ensure that our data gets updated that day to reflect the changes
> instantaneously.  I imagine it will be a year or two before OSi re-issue the
> Discovery Series (1:50,000) with the changes shown.  It will also be
> interesting to see how long it takes TeleAtlas (and thus Google) to update
> their mapping.

I totally agree. The last batch of redesignations, which included the
M6 from Kinnegad to Kilbeggan (and the then newly-opened piece from
Kilbeggan to Athlone) was done within a day or so of the order, and it
only took that long because I had to survey the newly opened piece. I
think that redesignation also incorporated the Carlow Bypass, but I
had already tagged that as motorway since the blue signs were already
up and it was in a kind of limbo where the eventual road class seemed
closest to What Was On The Ground.

> I'm not too familiar with the tagging process, but might it be an option to
> prepare for this event by adding a tag to all of the sections of N Road
> which are about to change, so that they can be easily changed on the day
> itself?

I'm with Tom on this one - it takes no time at all to use JOSM to
select all the ways involved and bulk update the ref and highway tags
(because that's all you have to touch). A second retag for the ramps
and it's oxo. It only requires that the retagger know the exact extent
of what's to be retagged. From recollection (since the article is
little help), you're looking at the following:

Dualled part of N2 north of Brock Inn exit
N4 as far a McNead's Bridge, but it's a featureless road on the map
and we'll need to check where the terminal junction is
N11 Arklow and Gorey Bypasses
N11 Rathnew/Ashford, though the northern extent here will need to be checked.
_Not_ N3 Clonee Bypass for the time being, as the M3 will have to be
complete to Pace for this.
N8 Glanmire Bypass. This is troublesome as the Act specifies this as
commencing 300ish m north of Dunkettle roundabout, meaning northbound
traffic has no escape route. Logic dictates the entire northbound way
from Dunkettle be tagged (the viral nature of motorway status), but I
can see this being open to dispute
N7: Limerick Bypass section, but how much of it?
N20: Anybody know exactly how much of it?

If we can find somebody with local knowledge for each one, I'd say we
can do it easily enough. We have plenty of time to plan it.

Dermot

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