[Talk-ca] Highway recoding

Sat Jul 25 17:10:11 UTC 2015

I think we are evolving to a consensus that makes sense. 

I have received some examples that are quite right in QC context. For those who know the area, Route 175 up to Saguenay is obviously a “type 1” trunk road while Route 138 northeast from Quebec City isn't.

However, I hope everyone concerned will give their “two cents” because the context in Manitoba or in Yukon may be (is) quite different, and I do not want an "Eastern centric solution" on the subject :-)

Best regards,

DanielI 

From: Daniel Begin [mailto:jfd553 at hotmail.com] 
Sent: July-24-15 10:09
To: 'Adam Martin'; 'Tristan Anderson'
Cc: talk-ca at openstreetmap.org
Subject: Re: [Talk-ca] Highway recoding

“… [TCH] is automatically a trunk route given that it is, at its most basic point, the central connection between major settlements …” 

Interesting… it is type 2 definition proposed by Tristan but without the concept of distance. IMHO, It highlights the fact that, depending on how you define central connection, major settlements, or distant population centres, you may ends up with the Britain situation – or even worst.  

Combining two very different objectives (types 1 and 2) in one definition leads to confusion. What about a rationale revolving around Type 1 definition but considering the TCH as a “special case” as suggested by Martin?

-          OSM road classes mostly aim toward Type 1 definition, so be it for trunks;

-          Since TCH could be consider as the only highway connecting most major population centres across the country, we could agree to tag it whether motorway or trunk depending on the infrastructure. There should then be no more confusion with this only one exception.

However, we could also manage all type 2 definitions, such as the ones described in document (a) with relation:route (b) but it is a bit more complex and less visual when looking at Mapnik. 

Other thoughts, comments?

Daniel

a) http://www.comt.ca/english/NHS-report-english.pdf

b) http://wiki.openstreetmap.org/wiki/Relation:route#Road_routes

From: Adam Martin [mailto:s.adam.martin at gmail.com] 
Sent: July-24-15 07:08
To: Tristan Anderson
Cc: Daniel Begin; Stewart C. Russell; talk-ca at openstreetmap.org
Subject: Re: [Talk-ca] Highway recoding

Reviewing the types that you suggest here, the result seems reasonable. Major Canadian Highways are generally a blend of the two, I find. Type 1 trunks rely on restricted access and the main highways in cities are generally limited in this manner. Likewise, these restrictions lift, in a sense, outside the city where they switch to connecting major settlements together (Type 2).

That said, I think that most would agree that the TransCanada Highway is automatically a trunk route given that it is, at it's most basic point, the central connection between major settlements, especially across provincial borders. I assume that the routes that leave the TCH to go to other major settlements would need to be at the same class as the TCH, if they are multi-lane highways used to connect settlements. Or are we to designate them down a classification and leave Trunk for the TCH alone?

On Thu, Jul 23, 2015 at 6:48 PM, Tristan Anderson <andersontristan at hotmail.com> wrote:

So it seems like we're coming to some agreement.  The current Canadian definition based on that 2005 document should be replaced with something else that is consistent with the rest of the world.  Once we find this new definition, the appropriate wiki pages should be updated.

I took a look around the world and finally saw some consistency in how trunk tags are used.  Stewart's guidelines are basically correct, but I think I can hammer out a more specific description.  There are two types of roads with are both usually tagged highway=trunk:

(1) Limited access highways.  This is a physical description for a road that has some of the characteristics of a motorway.  They are often dual carriageways of fairly high speed.

(2) Highways connecting distant population centres.  This is a functional description for a road where used by cars and heavy trucks travelling long distances or between major cities.  Although usually two lanes, in more remote areas these roads may have very light traffic, be unpaved, or be slow.

In some parts of the world, like Germany, France and the eastern United States, all trunk roads are type (1) because long-distance travel is generally done on their dense networks of motorways.

Conversely, in large swathes of Australia and Canada, as well as in much of the developing world, all trunk roads are type (2) because type (1) doesn't exist.

The only country I noticed that doesn't follow the above scheme is Britain (actually just England and Wales), ironically the birthplace of the trunk.  The designation there is used quite liberally, including even short roads connecting small towns and quite a few of of London's city streets.  Just look at England at zoom level 5 and observe how unusually green it is.

I suggest using the "international" model, with types (1) and (2) above being tagged as trunks in Canada.  This won't change much as it largely coincides with how roads are already tagged.  The wiki pages can be updated accordingly then we can look at specific roads in BC and Québec!

Any objections?

> From: jfd553 at hotmail.com
> To: scruss at gmail.com; talk-ca at openstreetmap.org
> Date: Thu, 23 Jul 2015 10:08:44 -0400
> Subject: Re: [Talk-ca] Highway recoding
> 
> Thank Russel,
> Your description is pretty close of the one I had in mind (about trunks) before I found the Canadian definition was referring to the mentioned document.
> 
> Cheers,
> 
> Daniel 
> 
> -----Original Message-----
> From: Stewart C. Russell [mailto:scruss at gmail.com] 
> Sent: July-23-15 08:44
> To: talk-ca at openstreetmap.org
> Subject: Re: [Talk-ca] Highway recoding
> 
> The definition of ‘trunk’ is a difficult one, if based on the UK understanding. Like its unwritten constitution, trunk roads in the UK are more on a "know it when I see it" basis.
> 
> Pretty much the only definitions I can think of that would be generally applicable are:
> 
> * a trunk road goes from one city/town to another.
> 
> * no parking at the side of the road.
> 
> * something above the urban speed limit applies (though there are often nasty brief exceptions, like a roughly 200m stretch of 30 mph that used to adorn the A80, dammit).
> 
> A trunk road isn't always dual carriageway. It can have traffic lights, roundabouts or (rare, in the UK) stop signs. Depending on its age, it may bypass towns and villages. Older trunk roads may also have all the usual roads entering it, while newer ones are likely to have on-ramps.
> 
> In summary, the UK definition is so riddled with unwritten exceptions that trying to apply it rigorously in even one province in Canada will be frustrating. And no matter what you do, you'll always get some rogue user that comes along and adds their own tagging. It's a sair fecht …
> 
> cheers,
> Stewart
> 
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