[Talk-us] US Trunk road tagging

[Paul Johnson]

On Thu, May 6, 2021 at 2:25 PM Minh Nguyen <minh at nguyen.cincinnati.oh.us> wrote:
>
> Vào lúc 11:00 2021-05-06, Paul Johnson đã viết:
> > On Thu, May 6, 2021 at 12:43 PM Kevin Kenny <kevin.b.kenny at gmail.com> wrote:
> >>
> >>
> >>
> >> On Thu, May 6, 2021, 13:30 Roff, Thomas (FHWA) via Talk-us <talk-us at openstreetmap.org> wrote:
> >>>
> >>> On the point of definition of an Expressway. We usually refer the Highway Capacity Manual for their definition. However, I am not sure if there is a legal definition in the US.
> >>
> >>
> >> There may be in some states. Around me, 'expressway' and 'freeway' are pretty much synonymous, so I actually have no idea what 'expressway=yes' might mean.
> >
> > I feel like Oregon/Washington have the strongest grasp on this, being
> > any two lane grade-seperated controlled access road (so, single
> > carriageway freeway type situation) or any dual carriageway high speed
> > freeway like road with intersections (including at terminus).
>
> In traffic engineering jargon, "freeway" refers to a controlled-access
> divided highway, while "expressway" refers to a limited-access divided
> highway or sometimes a controlled-access undivided highway ("super
> two"). As far as I can tell, the MUTCD doesn't define "expressway"
> explicitly, but it uses this term frequently, usually in the phrase
> "freeways and expressways". Occasionally, it distinguishes expressways
> when discussing at-grade intersections, which don't apply to freeways.

I think https://wiki.openstreetmap.org/wiki/Key:expressway actually
nails it pretty well and has a fairly complete view on what
expressways are.