[Talk-us] US highway classification

[Jason Straub]

Yeah, getting the definitions standardized has been thorny since day one.  I 
myself have had issues staying consistent from one road to the next.  There's 
just so much subtle differences between stretches of highways that make it 
difficult to say one way or the other.  Personally, I prefer the trunk being a 
non-limited access highway that has some type of divider.  Will use the Dumas to 
Texline stretch for example.  This stretch is the main trucking highway between 
Dallas and Denver, and is pretty much divided highway for all areas, excluding 
the stretches through the small cities that haven't been bypassed.  Otherwise 
this stretch might be considered a lonely stretch of little-traveled highway.  
This is where local knowledge comes in handy.  If standards could be agreed 
upon, then things would really fly.  Such are the perils of open sourcing...

Jason



On 5/27/2011 10:04 AM, Nathan Mills wrote:
> On Fri, 27 May 2011 09:26:41 -0400, Nathan Edgars II wrote:
>
>> No, trunk is also used for a major intercity highway that's not a
>> freeway. Take a look at the UK and their network of trunks.
>
> I'm sorry, I thought I posted to talk-us. My mistake. ;)
>
> Seems to me that trunk has no meaning if it is used in that way. In the
> UK, roads are classified based on the national government's
> classification of the roads (hence the confusing-to-us 'unclassified'
> tag. Since we don't have a single overarching national road network like
> that, I don't think that's a relevant model to use here.
How would you apply this argument to the use of primary to tertiary in 
the US?

> Generally
> speaking, I think any divided and controlled access highway probably
> ought to be tagged as a motorway barring specific local circumstances
> that cause it to deserve a demotion and any divided, but merely limited
> access and not fully controlled access, highway probably ought to be
> tagged as trunk barring specific local circumstances.
>
> The 'major intercity' road ought to be tagged as primary unless there's
> a specific reason to upgrade, IMO. That leaves the data more useful to
> end users.

Actually that leaves it less useful for users in cities, as then there 
are only two classifications for non-intercity highways, secondary and 
tertiary.
>
> Also, I don't know how major a road between Dumas, TX and Texline, TX
> really is. If it weren't a US highway, I'd probably demote it all the
> way to secondary.

It's on the National Highway System, meaning the FHWA considers it to be 
a major road. It's probably the best route between Kansas City and 
Albuquerque.

Also note the proposed translation on 
http://wiki.openstreetmap.org/wiki/Highway_Functional_Classification_System 
, used by at least one mapper in Kansas. Principal arterials range from 
expressways to major two-lane intercity highways.



------------------------------

Message: 3
Date: Fri, 27 May 2011 12:21:09 -0400
From: Nathan Edgars II <neroute2 at gmail.com>
To: talk-us at openstreetmap.org
Subject: Re: [Talk-us] US highway classification
Message-ID: <4DDFCF75.9080102 at gmail.com>
Content-Type: text/plain; charset=windows-1252; format=flowed

On 5/27/2011 12:00 PM, Alex Mauer wrote:
> On 05/27/2011 09:06 AM, Richard Welty wrote:
>> if you peruse the wiki, and make a reasonably through search
>> for definitions of trunk in the US, you will find an extensive
>> complex of contradictions and inconsistencies.
>
> Maybe someone should find all these and bring it up on the list so that
> a definition can be determined and the inconsistencies can be fixed?

I have tried in the past. The problem is that nobody can agree on which 
definition to use (even in the trunks must have four lanes camp, there's 
the Texas style, where everything with four lanes and a median is trunk, 
and the expressway style, where only limited-access surface expressways 
are trunk). Hell, even motorway is controversial (Seattle's Alaskan Way 
Viaduct is marked as trunk when it should be motorway).

I'm all for consistency, even if it's not the way I currently tag. But 
this doesn't seem to be an attainable goal.