[Talk-us] Update on potential highway classification reform

[Jmapb]

Thanks Kevin, you've really got the magic touch when it comes extracting
data from NY State.

My offhand impression is that this map has a lot red. That includes both
things I feel are oversold (eg NY-23 east of NY-8, currently tagged as
secondary) and things I feel are undersold (the NYC motorways... hard to
make out exactly what's going on in there, but there's hardly any blue.)

I don't know the west end of state all that well, or northern reaches,
so I can't speak to that. But this certainly passes the Ithaca-Rochester
test. And I do feel there's some value to employing the state's
knowledge/opinions in this process.

I fear we will, as you describe, end up with 50 to 56 different wiki
pages of highway tagging guidelines. So be it...

Jason

On 5/24/2021 4:20 PM, Kevin Kenny wrote:
> I think it makes sense for the OSM highway class to have rules at the
> level of individual states in the US, just as it has rules at the
> level of nations in the EU. Except for the Interstates, the US really
> has no national highway classification system. US highways are
> actually nowadays numbered by agreement among the states they serve,
> and the FHWA functional classification is intended to prioritize
> Federal aid for highway funding. Virtually all road designation,
> construction and maintenance is carried out by the states.
>
> New York's GIS appears to have classifications that make a modicum of
> sense. There's an Arterial Classification Code that attempts to
> document that-which-is (rather than allocate funding), for the express
> purpose of routing preference and decluttering at low zoom levels. Its
> top couple of levels of classification appear to be a decent match to
> 'motorway' and 'trunk'.
>
> Note that this is distinct from the Federal functional class, and the
> NY GIS system tabulates both.  Federal functional class is "what the
> road ought to be, and we'll use that to allocate funds for
> improvements', whie arterial class is "how the road actually is used -
> in terms of appropriateness for routing and zoom level"
>
> At the most significant levels, the chief points that are likely to be
> controversial:
>
> There are a few data entry gaffes. Most of these are obvious, such as
> the fishing access service way
> https://www.openstreetmap.org/way/20084827
> <https://www.openstreetmap.org/way/20084827> being classed as 'minor
> arterial', probably because it was inadvertently selected along with
> NY 23A.
>
> There are short motorway segments like NY 85 from I-90 to the first
> roundabout that are merely class 3.  (Then again, that segment is
> 'motorway' only by the 'three consecutive interchanges without a level
> crossing' rule. It has four.
>
> Some suburban freeways, and nearly all the parkways, are class 2
> rather than class 1. This list has seen arguments in the past about
> roads like these, with some people contending quite passionately that
> 'motorway' is inappropriate for a road with `hgv=no`, or for a
> suburban freeway that does not carry significant interurban traffic.
> The chief cause for the disagreements appears to be that for the
> larger cities, including the suburban freeway network clutters the map
> unreadably at low zoom levels.  Do we need an auxiliary tag to
> identify 'suburban freeway?' (Most three-digit Interstates, some NY
> parkways, NY 27 in Suffolk County, NY 33 and 198 in Erie County, and
> so on)?  It might help allay a lot of the arguments. I'd still tag a
> road `highway=motorway` if it's built almost to Interstate standards
> (both cross traffic and opposing traffic fully grade-separated with
> all entry and exit via ramps).
>
> The class-2 roads often end short of urban centers.  For instance, the
> one-way pair that carries NY 13 through the center of Ithaca is class
> 3.  This is understandable from the routing perspective; for instance,
> it encourages drivers to bypass Manhattan unless their trip starts or
> ends there. There is also a glitch or two - as with any data set. In
> the Ithaca example, one block of West State Street between the one-way
> pair is inexplicably marked as class 2.  I suspect this, and the
> downgrading of NY 13 south of town where it splits very briefly into a
> one-way pair at the NY34/96 junction, are simple data entry errors.  I
> think that all of these issues could be resolved with a topology
> check: if a trunk's classification dead-ends within a couple of miles,
> say, of another trunk in the same route relation, or contains routing
> islands, flag that bit for manual patchwork.
>
> On the other hand, it might make sense for a trunk to end a little bit
> short of a city center if it carries significant traffic into and out
> of that city, but is unlikely to be a significant conduit for
> intercity traffic not visiting that city. I-95 across the extreme
> northern end is just about the only case in Manhattan where a freeway
> or trunk road carries traffic for which New York City is not a port of
> call.
>
> The odd quad-carriageway Queens Boulevard / NY 25 is merely a
> class-3.  It makes sense, I suppose, given that the ten or twelve
> lanes really just barely carry the local traffic.
>
> Following the New York State classifications for New York roads,
> except as necessary to patch topological inconsistencies, would
> deflate most arguments that the classification, at least here, is
> inherently subjective - it's at least the subjective judgment of the
> arm of the government that's responsible for the upkeep of the highways.
>
> The result looks decently connected if a bit sparse. What do others
> think here?
> http://kbk.is-a-geek.net/attachments/20210524/NY-class-1-2.png
> <http://kbk.is-a-geek.net/attachments/20210524/NY-class-1-2.png> -
> blue is class 1 (essentially all `motorway` except for the missing
> part of NY 17), red is class 2 (some of these are also motorways, but
> could disappear at low zoom; the rest are the trunks).
>
> -----------------------------------------
>
> (Supplementary details follow.)
>
> From the metadata:
> (http://gis.ny.gov/gisdata/supportfiles/Streets-Data-Dictionary.pdf
> <http://gis.ny.gov/gisdata/supportfiles/Streets-Data-Dictionary.pdf>):
>
> > ACC: Arterial Classification Codes (ACCs) categorize roads according
> to the level of travel mobility that
> > they provide in the road network. Mobility refers to the volume of
> traffic that a stretch of road carries and the
> > length of trip that it serves. Roads at the highest level of
> mobility serve the greatest number of trips and the
> > longest trips. Conversely, high-mobility roads provide the lowest
> level of access to property. Low-level, local
> > roads serve that function.
>
> > This system uses a six-level system, with 6 as the lowest level, 1
> as the highest. A list of the Arterial
> > Classification Codes is in Table 2 below. Ascending through the
> levels, each step represents an increase in
> > relative importance to routing – an increase in the number and
> length of routes using the road. In general, a
> > step up also represents an increase in traffic-volume capacity of
> the road, an increase in vehicle operating
> > speed, and a decrease in travel time. (This system is similar to,
> but not tied to, the Federal Highway>
> > Administration’s Highway Functional Classification System.)
>
> > The primary use of ACCs is in automated routing. Using ACCs, a
> routing program calculates the maximum use
> > of the highest-level roads that are appropriate to the scale of the
> desired trip. This is analogous to the route
> > planning of a typical driver, who uses the highest-speed road
> available, within the geographic range
> > established by the origin and destination points. The hierarchical
> nature of the ACC levels allows for more
> > efficient access to relevant routing networks for a given route, and
> in turn reduces system requirements.
> >  The implementation of ACC also supports its usage for map
> rendering. Using ACC as a cartographic tool
> > allows for a variety of enhancements including:
> >    1. The display of “important” roads.
> >    2. Reduction of line density and visual clutter based on scale of map
> >    3. "Visual Routing" on paper maps (the end user chooses a route
> based on ACC display)
> >    4. Effective zoom layering in digital applications
>
> The table for 'arterial classification' is complicated and appears on
> page 15 in the document linked above.
>
> Kevin's summary of ACC's as they appear actually to be used:
>
> 1. Most major through-roads for interstate commerce. (Two-digit
> Interstates, plus a handful of similar roads such as NY 17, the
> Berkshire Spur, I-495 east of the Cross Island Parkway interchange,
> I-390, I-684 and the Hutchinson River Parkway.  All of the ones I
> observe in New York are properly `highway=motorway`, with the sole
> exception of the short non-motorway segment of NY 17 between Deposit
> and Hancock, which is also what keeps NY 17 from being designate I-86
> (much of it is signed 'Future I-86'.
>
> 2. Many three-digit Interstates. Most state parkways. Most US Highways
> (4, 44, 20, 9, 9W, 209, etc.) outside the cities. NY 7 between
> Bennington and Troy, between Latham and Niskayuna. NY 25 and NY 27 on
> Long Island.  Also, many lesser roads in the hinterland that carry
> great local economic significance.  In particular, for Russ Nelson's
> concern that the classification would leave communities north of the
> Adirondack Park isolated, US 11 would be included, as would NY 56 from
> US 11 to Massena, NY 37 from Massena to the Cornwall border crossing,
> and NY 812 from NY 12 to the Ogdensburg border crossing. Addressing
> Jmapb's concern, Ithaca is served by a single trunk (NY 13) that joins
> it to the two nearest motorways (NY17 and the Thruway), and then a
> whole radiating star of class-3 roads.  In Manhattan, it's the ring
> road (West Street, Henry Hudson Parkway, FDR Drive) surrounding the
> island, plus connections to the tunnels (Lincoln, Holland,
> Brooklyn-Battery/Hugh Carey, Queens-Midtown) and certain bridges
> (George Washington, Manhattan, Williamsburg, and Triborough/R.F.
> Kennedy), including the crosstown arterials of 34th Street and
> Delancey and Canal Streets, and roughly mile-long sections of 8th, 9th
> and 10th Avenues and 14th and 23rd Streets needed to get vehicles
> between the tunnel entrances and the ring-road interchanges. A handful
> of surface streets in the immediate vicinity of the other tunnels are
> included. In the outer boroughs, almost all the freeways are class 2.
> (The class 1's are the two-digit interstates, the Hutchinson River
> Parkway and the Throgs Neck Bridge.)
> I-495 east of the city line and the segment of the Cross Island
> Parkway that connects it to the Throgs Neck Bridge are the only class
> 1's on Long Island. The class 2's appear to include all motorways,
> plus NY 25 Truck (not NY 25 where the truck route parallels it), NY 24
> and NY 27 at the East End.
>
> 3. Intra-state and intra-metropolitan primary roads.  These are
> something of a mixed bag. Note that they do NOT include all of the
> numbered state highways, and this is appropriate (some are really
> local connector roads or don't really serve any fair-sized towns. 
> These look to be a good fit for `highway=primary`.
>
> 4. 'Minor arterial'  These would be a good match to
> `highway=secondary` except that physical characteristics enter into
> the state's classification too much, creating routing islands at this
> level.  In any case, primary/secondary/tertiary is not the immediate
> question.  I think `minor arterial` could be a really good starting
> point, though, with some small amount of manual patchwork required.
>
> 5. Pretty much everything else in the public road network: tertiary
> and unclassified highways, residential streets, urban collector roads
> that don't rate 'secondary highway', and so on.  The local streets.
>
> 6. Almost all class 6 roads are the access roads for apartment
> complexes, commercial establishments and industrial facilities, and
> `highway=service` looks to be appropriate for most of them. (For the
> smallest ones, the usual arguments among 'service', 'track',
> 'residential' and 'unclasified' come up. I'm not going there in this
> message.)
>
> A rough idea that I think could work for New York:
>
> Class 1 roads - All 'motorway', except that the anomalous section of
> NY 17 would have to be downgraded.
>
> Class 2 roads - These should be 'motorway' if they are built to
> near-Interstate standard, 'trunk' otherwise.  They need topology checks.
>
> Class 3 roads - These are all at least 'primary'. Topology might
> require upgrading some of the rest of the network to avoid routing
> islands at the 'primary' class.
>
> Class 4 roads - These should all probably be at least 'secondary' -
> including some only-partially-paved roads like Ulster County Route 47,
> where they've pretty much abandoned the attempt to preserve a hard
> surface through the mountain pass, but which provides the only access
> to the Oliverea valley. There are a lot of routing islands to patch.
>
> Class 5 roads - I'd argue that any numbered county highway (whether or
> not the county signs its numbered highways, so Westchester and Nassau
> Counties count!), any state touring route, or any state reference
> route (These last are all unsigned, with four exceptions) rates at
> least 'tertiary'. Otherwise, we're down at the 'local road' level, and
> we know what a morass 'unclassified', 'residential', 'service' and
> 'track' have become.
>
> Class 6 roads - Usually 'service', but again we have the morass of
> 'lowest-level roads' to deal with.
>
>
>
> --
> 73 de ke9tv/2, Kevin
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