[talk-au] (LONG) Adelaide Highway Classification (was: Highway Classification Issues)

[Darrin Smith]

Wups, sent the previous email just to Stuart not the list, got to watch
out for these people who CC lists...

 On Mon, 10 Mar 2008 23:37:46 +1100
"Stuart Robinson" <brainwad at gmail.com> wrote:

> I think you are far too eager to mark every other highway as trunk.
> Sydney also seems dilapidated of trunks cause the motorways have
> superseded a lot of arterial metroads along their routes.

I implicitly was counting them as turnk routes, Melbourne still creams
Sydney for trunk density.

> Looking at Adelaide, certainly A22 is *not* a trunk route, it should
> primary. Trunk routes should be in the order of 50km or longer (all
> but one Sydney metroad is, and that one is because it goes north and
> the city just runs out of space). The A13 should not be trunk,
> because it seems to me that the (NH)A20 is the main route north east,
> and the A13 just parallels it. Same with Lower North East Road and
> North East Road. The one that is the main road out to that area
> should be trunk, the other should be primary. The A15 looks like it
> just parallels South Road too, but I can at least see an argument for
> that one. Also: is Main North Road or NHA17 the more used northern
> route? Because whichever is the more long-distance route (I'm
> thinking/hoping this is the NH) should be the trunk, and the other
> should be primary.

Simply shot down in Sydney by M3 and M6 which are closer than some of
the roads you are talking about and cover nearly identical tasks
(middle ring route). So will you be removing one of them? No, because
they are Metroads, because a non-job-specific definition is labelling
those as the routes. The A13 pulls traffic from the NHA20 to a
completely different part of the city to the road itself, as do the M3
and M6 when you look at them in detail. 

(As I've said in an earlier post I'm quite happy about rejecting the
A22 if we decide to reject any, this issue is whether we apply a simple
consitent definition or base our decision on whatever mood someone is
in because of what they are for breakfast that morning?)

We are trying to work out a similar thing in Adelaide. As soon as you
don't have a definite thing you start getting arbritary definitions
like "50km in length"  why not "60km in length" oh, that would drop
another 3 of yours off the list and it wouldn't be some comprehensive.
What makes 50km special?

> So in conclusion, trunks are through routes, primaries are major
> highways. through routes aren't necessarily of high standard (think
> two lane rural highways, like the northern road in Sydney), and high
> standard highways aren't necessarily through routes (though they
> might have used to have been, i.e. no one would seriously use the
> Hume highway between Sydney and Casula any more, they'd use the m5,
> even though some sections of the hume highway are quite good
> standard, the road is now only for local traffic, not through traffic
> between Sydney and Melbourne).

That works raelly well in sydney where the entire basin has only a
limited number of entry points (6 by my count).
In real cities that contact the entire countryside around them there
are numerous through routes running out of the city that are over 50km
long and no-one would concieve of making them trunks.

Using Sydney as a typical example for this doesn't cut it, Melbourne
matches a lot closer and it has a density of trunk routes similar to
Adelaide.

-- 

=b