[OSM-talk-ie] National Road Network - mostly complete

[Dermot McNally]

2008/5/20 Paul Cunnane <paul at cunnane.net>:

> It has occurred to me on a number of occasions that the remaining task
> is still pretty huge. Our road network is almost impossibly dense for
> the size of the country.

It is, yes. Particularly if you consider every boreen and track.

> It makes sense to concentrate on the nationals first: primary then
> secondary. Then the R routes need to be done. Once it gets down to the
> tertiaries and unclassifieds, the task gets much harder.

Absolutely. But remember that having all N's and R's puts us in an
excellent place, and should generally allow navigation to any
"navigation point" (by which I mean "the village nearest wherever
you're headed). We already have many areas in Ireland, both urban and
rural, that have very detailed mapping, and this reflects the fact
that this level of mapping is achievable once some interested person
forms the habit of collecting tracks.

> I'm working out a plan in my head to systematically map every road
> within a reasonable distance of here by marking off "quadrants"
> delineated by a combination of N- and R-roads, and coastlines, and using
> recursive left turns to map everything within each quadrant, perhaps
> dedicating half a day's driving to each quadrant. Interleaved with this,
> I'll do similarly detailed mapping of the streets in Mayo's towns.

That's basically the approach we took during the Dublin mapping party.
It works well, but you need to have chosen a sector size that you can
actually complete. I think that a certain amount of casual dot-joining
can work well too, and will give us useful boundaries for detailed
surveys. Simply driving down a back road not yet mapped because it
fills a void.

> Thing is, assuming I can dedicate half a day a week to this, there must
> be a year's work in Mayo alone. We're going to have to find a way to get
> more people involved, without diluting the quality of the surveying and
> mapping.

Don't worry - it will get done in time. And the map, even in its
current form, is already very usable. Infill will happen where OSM
users go and there turns out to be gaps. More mappers will increase
the pace. More applications for the data will provide great traction.
The day is not far off when an OSM-powered vehicle navigation system
will be practical, and that will get many more people on board.

When I first started using satnav in Ireland, just Dublin and Belfast
were mapped. Badly. It took Navtech (as they were then) many years to
fill in the gaps. I started mapping for OSM less than 2 years ago. At
that time, there was very sketchy coverage of Dublin and Cork and
basically nothing else. Not even coastlines. To me, the rate of
progress is extremely impressive. We don't need to worry yet.

Cheers,
Dermot

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