OpenStreetMap
The case for highway=trunk on Texas frontage roads
Diposkan oleh clay_c pada 24 September 2017 dalam EnglishYou can tell where someone’s from in Texas by what they call that smaller road parallel to the highway. A Dallasite may call it a service road, a San Antonian might say access road, and every other Texan will tell you it’s a frontage road, except of course Houstonians who swear by feeder. Regardless of what you call it, it’s a ubiquitous thing across the urban areas of Texas. Everyone’s driven on ‘em.
So why are they so chaotically mapped?
As it is right now, they’re typically mapped as highway=secondary throughout, switching to highway=primary or even highway=trunk when they’re part of a freeway exit for such a road. This happens regardless of the lack of any underlying changes to the frontage road itself. If I showed you a cropped image of a frontage road segment tagged highway=secondary and another nearby segment tagged highway=trunk, you probably wouldn’t be able to tell the difference.
This ends up looking kinda janky and ugly. But more importantly, it doesn’t do a good job of describing the roadway it’s supposed to represent. If you take out the freeway and leave just the frontage roads, it’s a wide boulevard with massive spacing in between median crossovers. That alone merits highway=trunk.
And, lo and behold: we already do that where the freeway hasn’t yet been built but its surrounding frontage roads have been.
In good faith, I’m going to be changing most urban Texas frontage roads to highway=trunk. I hope this makes sense to people, and if you have any concerns, feel free to shoot me a message.
-Clay
Discussion
Ulasan Polyglot terhadap 24 September 2017 pada 08:46
Hi Clay,
I see highway=trunk as somewhere between highway=primary and highway=motorway, referring to their importance.
If the inner dual carriageway is highway=primary, I would tag the outer secondary or tertiary.
If you want those to look more important, you could use highway=primary/secondary for the outer pair and highway=trunk for the inner pair. If the inner pair resembles a freeway, that is.
Ulasan maxerickson terhadap 24 September 2017 pada 13:35
What about all the traffic lights and at grade intersections?
The definition of trunk I try to argue for is the regional road network. The function of these roads is pretty local, mostly providing freeway access.
Why not get rid of the here-comes-a-freeway primary classifications by making them secondary (or whatever makes sense for the local frontage)?
Ulasan Baloo Uriza terhadap 24 September 2017 pada 15:29
Depends on the frontage system deployed. Rural frontages, I’d tend to call tertiary save for the sections feeding from and to the motorways to the relevant cross street.
Urban contexts where the system is one-way? At that point you have a surface expressway, which is normally a trunk, that has a freeway (motorway) down the median of it. I agree in the situations where the outer roadways are one-way and go through, the outer roadways should be trunk.
Ulasan Richard terhadap 24 September 2017 pada 18:56
Eeek.
highway=trunkfor frontage roads doesn’t make any sense to me.The
highway=tag is meant to reflect a road’s importance in the through-highway system. It isn’t solely a reflection of physical characteristics.A frontage road is by definition unimportant in the through-highway system: its purpose is to serve local traffic (and, importantly, to provide an alternative route for traffic that might be prohibited or uncomfortable on the main road, such as bikes or slow-moving agricultural vehicles).
That suggests
highway=tertiary, orhighway=secondaryat a pinch. Definitely not trunk.Ulasan Baloo Uriza terhadap 24 September 2017 pada 19:01
The rural Texas frontages, I definitely agree with Richard on. However, the urban version, such as you find on TX 121 where the Sam Rayburn Turnpike runs down the median? That’s pretty much a textbook trunk already.
Ulasan Richard terhadap 25 September 2017 pada 09:03
Have just spent half an hour down a Google Street View (wash my mouth out…) rabbit-hole. :)
Hooee, that’s a difficult one. Having a frontage road as trunk really does seem to break the purpose of the highway tag, but on the other hand the physical characteristics in this case are pretty compelling. So I can see your point now along TX-121, though I could also see the case for
highway=primarywith alanes=tag.But (say) the road alongside I-35 in Waco looks fine as a secondary to me, or could even be a tertiary. Alongside US-34 in Waco is either tertiary or unclassified.
Ulasan Baloo Uriza terhadap 25 September 2017 pada 15:12
Yeah, that gets fun in Texas. I’d probably consider Dallas Parkway a Primary because of the frequency of driveways and intersections, despite being the outer roadways to the Dallas North Turnpike. But, the newer four-way motorways (which are the standard in Texas anymore) do tend to have more of a SRT/TX 121 layout.
Blanket rule doesn’t really work, still should be on a case-by-case thing on the Texas 4-way motorways.
Ulasan skquinn terhadap 13 Mac 2018 pada 10:24
I say leave them as is. Making them all trunk, except where they connect to a trunk road, is just going to make a mess and make it harder to tell where the real trunk roads are.