[Talk-us] Trunk

Paul Johnson baloo at ursamundi.org
Sun Oct 8 18:26:48 UTC 2017

A little context, since I don't know how routine it is for folks to be
aware of the difference between an expressway (which is what I would call a
trunk in OSM terms) and a freeway (OSM's motorway).  I use the same
criteria as AASHTO, where a freeway is always dual carriageway, fully
controlled access, and no direct access to abutters.  Expressways would be
partially controlled dual carriageway with limited or no direct access to
abutters or fully controlled single carriageway with no direct access to

On Sun, Oct 8, 2017 at 1:02 AM, Dave Swarthout <daveswarthout at gmail.com>

> >I'd hazard to guess Alaska has considerably more "trunk" than "motorway"
> miles, particularly outside of metro Anchorage.
> Agreed.
> Here's a query for the George Parks Highway that runs between Fairbanks
> and Anchorage:
> http://overpass-turbo.eu/s/scw
> no relations, only ways are involved

Relation 331099 (highway A3), looks like.

Looks like a motorway from where it leaves A1 to the end of the median just
west of Seward Meridian near Anchorage.  Assuming Bing's imagery is
current, it should be mapped as a single carriageway, and I'd call that a
primary typically until it becomes a two lane road, and after that as a
secondary (since it's a state highway, that's the lowest I would take it)
until median starts again just west of Geist Road in Fairbanks where it
goes dual carriageway and becomes a motorway again (I wouldn't consider any
single carriageway as a motorway).  I would not normally consider a
single-carriageway without full access control (ie, exclusively accessible
via freeway style ramps) as a trunk.  *However*, its status as Interstate
A4, I would be inclined to call it a trunk anyway for that reason alone,
for the entire distance that it's not a motorway.

In Fairbanks, specifically, I'd call that dual carriageway a trunk from
where it begins on the west end to where it ends at A2, and not a motorway,
even if it wasn't an interstate, because of its mix of ramps and
intersections; it's definitely not a motorway in Fairbanks.  Motorways
shouldn't have intervening intersections or terminate on an intersection.
Trunks can have a mix of intersections and interchanges.

The relation for A3 was a hot mess, I couldn't resist the urge to clean
that up and make it easier for y'all to maintain, but I did *not* change
the tags or geometry on any of the ways.
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