[Talk-us] "highway" tags in the US
hawke at hawkesnest.net
Tue Mar 4 16:26:19 GMT 2008
Karl Newman wrote:
> Karl Newman wrote:
> > Okay, for trunk, how about *mainly* ramp access, with grade-level
> > crossing access to side roads permitted, but without traffic
> controls on
> > the highway where they meet?
> Hmm, I don't think the ramp access should be a requirement. Agreed on
> "without traffic controls on the trunk highway at intersections" though.
> I said mainly, not all. Otherwise, why wouldn't you just make it primary
> in that case?
Dual carriageway, higher speeds. Built similarly to a motorway, but
without the restricted access.
> Around here the county roads vary widely in speed limit, anywhere from
> 30 to 55 mph. They all seem to be two-lanes (total, not per-direction),
> with fairly narrow shoulders.
> My guidelines are thinking about expectations, as well. What you say
> about county roads basically says that you have to lower your
> expectations about them, because you don't know what the road is going
> to be like or how fast you'll be able to travel it.
> > So you would place unclassified above tertiary? I haven't spent much
> > time looking at road classifications when I've been in Europe (I
> > probably would now since I've joined OSM), but that seems to go
> > the existing guidelines.
> No...I use tertiary as you describe "missing_tag":
> "residential branch roads which are main roads
> through subdivisions..." though, I don't see why it should be exclusive
> to residential/subdivision areas.
> I noticed now there's also a difference in your usage of unclassified;
> As I use them, these are ordinary, unremarkable roads; if they were in a
> residential area, they'd be highway=residential. So I put
> "unclassified" down a level from where you do, in between your
> missing_tag and residential.
> Then why should we even distinguish between unclassified and residential?
As far as I know from the history of OSM unclassified and residential
are basically the same, and they render the same in pretty much every
renderer. I believe it's a historical artifact where "residential"
pretty much meant "unclassified+abutters=residential".
> The first part of your description of unclassified seems to fit there,
> as well: "urban commercial district or rural low-density housing..."
> I suppose we differ in that I feel that tertiary can scale: in a
> residential area, it's the "main roads with fewer driveways", in a
> commercial or industrial area, it's the main roads as well, and in rural
> areas it's main roads which are not county highways.
> I think it's not so good to make the tertiary tag cover all those cases.
> As you've described it, in a residential neighborhood, that road is
> generally 25 MPH, in a commercial or industrial area it's usually 35
> MPH, and in a rural area, 40-55 MPH. I think only last one makes sense.
Other roads change speed as they enter urban places (e.g. primary roads
may go from 55 down to 25 to pass through a hamlet) Why shouldn't
tertiary be the same? It's all about the relative status of a road to
the roads around it.
> I would not use "direct driveway access" as a factor for distinguishing
> highways. Roads of all classifications except motorway may have direct
> driveway access, especially in rural areas.
> It's just a guideline, and it goes toward expectations. Driving down a
> residential street, I expect to have to watch carefully for kids playing
> or for drivers backing out. I realize that almost any road can have
> direct driveway access, but it's very infrequent (more like every 1/4
> mile at least, not every 100 feet as in a residential neighborhood). On
> a more heavily-traveled road with a higher speed limit, the driver
> pulling out has to be more careful than the through traffic.
Hmm...it seems to me that perhaps you're writing this from a perspective
of "what a driver using the road might expect", while I'm coming from a
perspective of "how should this road be tagged". Is that the case?
-Alex Mauer "hawke"
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