[Talk-us] Trunk

Evin Fairchild evindfair at gmail.com
Sat Oct 14 17:49:23 UTC 2017


To add onto what Bradley was saying about third-party applications, I just
want to add that I've done some fact-checking about a claim that Paul made
in a previous email about how Osmand renders trunks under the assumption
that they are expressways (to be clear, by this I mean divided highways w/
at-grade intersections). After some fact-checking, this claim receives a
truth rating of *completely FALSE*.

Anyway, I looked at how Osmand renders motorways versus trunk and I don't
know how it is that you, Paul, can say that trunk is assumed to be like an
expressway  in Osmand's render. That is simply not true. The motorway in
Osmand, for those who are unfamiliar, is red with a thin blue outline
around it, whereas trunk is just an orange-red line without any other color
outlining it. This makes it look more like a single-carriageway road and
less like an expressway like Paul falsely claims. All it looks like is a
road that is of higher-importance than primary, and does NOT at all look
like it could be an expressway. Usually, when maps show a divided highway
w/ at-grade intersections, it looks similar to a freeway, but a different
color, whereas an undivided two-lane road typically looks nothing like an
expressway or freeway. Thus, it is complete and utter lie to say that
Osmand makes the assumption that trunk roads are expressways. I don't know
how mkgmap shows trunk vs. motorway since I don't have a Garmin and thus
cannot test it out, but I don't trust that Paul is telling the truth here
either.

It's important to make truthful claims here, Paul; from now on, I will have
a VERY difficult time trusting anything you say. I know what I brought up
was kind of a side point, but I think it's important to call out BS when I
see it.

-Evin (compdude)


On Sat, Oct 14, 2017 at 10:23 AM, Bradley White <theangrytomato at gmail.com>
wrote:

> > The concept of expressway and freeway are reasonably well known concepts;
> > it makes a lot of sense to map trunk and motorway to those concepts.
>
> I agree with freeways but not with expressways. I have no data to back
> this claim up, but I'm fairly convinced that, while the average
> citizen could easily differentiate between "freeway" and "not
> freeway", they would be hard pressed to do the same with an
> expressway. Anecdotal, but even when I spent time in the Santa Clara
> area which has a robust expressway system, I never heard a single
> person say "and then get on the expressway...", or even the word
> 'expressway' mentioned outside of it being the suffix of a road name.
> You're right that it's not a terribly difficult concept to understand
> and thus map, but I disagree that it's an important concept in
> explaining the road hierarchy in the US, so much so that we can equate
> an entire class of importance with them. We have a robust, clearly
> signposted freeway network in the US. We do not have the same with
> expressways. Roads tend to go in and out of "expressway" qualification
> depending on context, traffic levels of connecting roads, and highway
> budget & design policy. A road being built as an expressway is
> suggestive of its importance at best, and certainly not indicative.
>
> Edmonton has many roads around the east and west of the downtown area
> that are clearly built as expressways. However, they are only tagged
> secondary because, fundamentally, you only really need to use them to
> get around the immediate vicinity. Despite being very high quality
> roads, they aren't all that important in the grand scheme. I can point
> to many examples of urban roads that likely meet an expressway
> definition in my current home city of Reno, including one under
> construction. It would be absurd to me to tag them as being second in
> importance only to motorways just because they are well-built roads,
> because they're unimportant outside of getting around the relatively
> small Reno-Sparks metropolitan area.
>
> The "highway" key is about importance. The only category we have
> full-stop made equivalent with a type of road design is "motorway".
> From trunk on down, it is just different grades of importance. These
> are how the definitions are listed on the 'Key:highway' page, which I
> consider to be definitive. The fact that the words "trunk", "primary",
> "secondary", ... are used is an artifact of the UK roots of OSM. Had
> this project started in the US, the keys would probably be "freeway",
> "principal_artery", "major_artery", "minor_artery", "major_collector",
> ... leaving UK users scratching their heads trying to figure out how
> to adapt these definitions to their own network. In countries with
> signposted expressway systems, it is meaningful in understanding the
> road network to equate trunk with expressway, so they do that. I don't
> think doing the same is meaningful in the U.S. given how much
> variability and inconsistency there is with how and where expressways
> are constructed.
>
> > Even a lot of renderers make this same assumption:  mkgmap maps trunk to
> > Garmin's concept of expressway and motorway to freeway.  Osmand, easily
> the
> > most popular data consumer for OpenStreetMap, makes the same assumption
> (to
> > the point that most of it's map painting styles, the only differentiation
> > between trunk and motorway is a color pallette shift).  It really
> wouldn't
> > hurt the US community to have a "come to Jesus" moment on this,
> > particularly when using the MUTCD definitions for expressway and freeway
> as
> > qualifiers for trunk and freeway, makes this relatively easy.  The
> > corollary to "don't tag for the renderer" is "don't break the renderer".
> > Highways without access control being excluded from trunk or motorway
> isn't
> > an intrinsically bad assumption to make.  Especially if we come to
> > agreement on that, we can start having a productive talk on how to make
> > carto not suck for Americans without breaking it for everyone else.
>
> I'm really not that concerned with how third-party applications decide
> to paint their roads. It's up to them to work with the data we
> provide, not the other way around. If it is important to Garmin or
> other applications to translate expressways, this can usually be
> deduced from other tags, or we can trivially add an "expressway=" tag.
> I also disagree that the carto in the US is bad, other than our
> insistence that two-lane are categorically not trunk leaving
> meaningless splatters of orange around the map at low zoom.
>
> Also, apologies ahead of time if I keep breaking the archive
> hierarchy, I'm not totally familiar with how to drive a mailing list
> and I have yet to find a guide online that explains how.
>
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