[Talk-us] Trunk versus motorway

Paul Johnson baloo at ursamundi.org
Fri Nov 30 02:34:57 UTC 2018

I'm largely in agreement and this seems like how it's been done in
practice.  Would also apply to WA 500 (which also should be a trunk east of
I 205, if not at least 112th/Gher; with argument supporting 205 being that
112th/Gher is largely only used by way of it's I 205 North exit and
supporting Gher as the break as it doesn't start slowing down until just
before the WA 500 East merge), and until recently, the entire length west
of the traffic light with Fourth Plain.

There's been a long tendency towards escalating highway priority, which
kind of dilutes all of the definitions and overloads secondary, primary,
trunk and motorway, that I've been trying to resist.  Like US 26 from where
it goes single-carriageway east should be primary, same with US 97 north of
Bend Parkway
 and south of Century Drive
the Klamath Falls Pilot
then again south of Reams Country Club
to use some more examples I'm very familiar with on the ground.  About the
least motorway-like thing I'd call a motorway would be Arroyo Seco Parkway
(most ramps are RORO with stop signs and no merge space, really not having
changed much since it was parodied in 1950's Motor Mania

Single carriageway grade separated?  Trunk.  Dual carriageway, at-grade
intersections but otherwise freeway like?  Trunk.  Traffic lights?  Trunk.
Fully controlled, fully grade seperated, high speed design?  Motorway.
Random 100km+ stretch of standard interstate-style highway
 (TLDR version
that passes a cow pasture whose only frontage is the freeway, accessible
only through a private gate in the freeway fence?  Motorway.

Another set of situations I'm familiar with:  I 5 north of WA 543 (trucks
prohibited, frequently stopped traffic to that point, speed limit gets down
to 10 MPH, passes through several crosswalks, then not long after that and
enters Canada, and doesn't properly continue as freeway again until the 8
Ave interchange on BC 99.  Nearly the mirror situation at the opposite end
of I 5, it and 805 south of the San Ysidro interchange with the Mexican
side currently mapped correctly.  Neither are remotely like, say, taking
Germany's A 6 onto France's A 320 where everything's free flowing, and no
checkpoint and not driving in a park.  A really good edge case would be
between motorway and trunk would be I 5 between OR 99E and WA 14 (traffic
lights for/and a draw bridge, no shoulders, and a blind sharp right turn at
the north end northbound).

On Thu, Nov 29, 2018 at 7:36 PM Greg Troxel <gdt at lexort.com> wrote:

> Bryan Housel <bhousel at gmail.com> writes:
> > Can’t a motorway begin or end at an at-grade intersection though?
> Certainly, and I think the question is how long does a stretch of road
> that meets motorway specs have to be to be tagged motorway.  The basic
> issue is that "not having at-grade intersections" is not a local
> property of a road, and is really a statement about the road before and
> after where one is talking about.
> Assume an infinitely long road, divided, 2 lanes each way.  After a very
> long time of no intersections, assume an at-grade intersection, and call
> this coordinate 0, expressed in km.
> Then, assume an another at-grade intersection at 0.100.  After that, at
> 0.110, and so on, with each being 1.1 times the previous.
> By the time you get to 500 km between at-grade intersections, the
> intevening roads are surely motorways.  At 100m, they surely are not.
> In my view, to be tagged as motorway, the length of qualifying roadway
> has to be long enough so that it feels like it is very long, as opposed
> to a lucky 2 to 3-mile stretch of trunk that happens not to have any
> intersections.
> Overall, I would throw out that if a section that meets motorway specs
> isn't at least 10 miles, it's still really nice trunk, and should not be
> tagged motorway.  Maybe 10 is too much and it should be 5 mi, or 10km,
> or maybe it should be 20 or 25 km.   But 1-2 miles is way too short to
> flip back and forth.
> I have no  idea if this supports or opposes Paul in this case :-)  But
> I'm guessing it supports...
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