[Talk-us] United States Roadway Classification Guidelines

[Nathan Edgars II]

On Tue, Jul 27, 2010 at 9:24 AM, Ian Dees <ian.dees at gmail.com> wrote:
> On Tue, Jul 27, 2010 at 8:00 AM, Nathan Edgars II <neroute2 at gmail.com>
> wrote:
>>
>> On Tue, Jul 27, 2010 at 8:24 AM, McGuire, Matthew
>> <Matt.McGuire at metc.state.mn.us> wrote:
>> > This looks like coding for the map rather than mapping what’s on the
>> > ground.
>> > I understand that a highway’s importance to an area is relative to other
>> > highways in the area.  But that doesn’t mean a two lane at-grade highway
>> > should be coded the same in one area as a four lane limited access
>> > highway
>> > in another. Or perhaps there should be another tag for the type of road
>> > as
>> > experienced on the ground vs a state or national scale map.
>>
>> We have those tags: lanes=*, width=*, etc. But there's no "on the
>> ground" definition of importance,
>
> Yes there is. It's the highway= tag.
Please explain?
>
>>
>> and there's nothing wrong with
>> tagging correctly for the renderers.
>
> Yes there is. "Tagging for the renderers" is the first thing people in OSM
> will tell you *not* to do.
That's tagging *incorrectly* for the renderer that you don't do.
>
>>
>> Classification has been
>> subjective from the beginning in the US, because there is no
>> consistent government-assigned classification.
>
> That is incorrect. There is a relatively consistent government-assigned
> classification system. It has been linked to several times on this list
> (most recently by the originator of this thread).
Can you give a link to it?

> The problem is that the
> European community has decided that the highway tags are shorthand for
> physical qualities that usually only exist in Europe.
I don't know about other countries, but in the UK the classification
has nothing to do with physical qualities; it's tied to a consistent
importance-based system assigned by the government.

> The suggestion I made
> in my first reply to this thread was that we use a separate tag to describe
> what the US government calls the way. This would allow us to make an
> interstate-only road map like the one that Google shows you or that you can
> obtain in paper from your state government.

And what do you do for all the not-so-major roads that the US
government doesn't care about (anything not an Interstate or on the
National Highway System)?