[Talk-us] Update on potential highway classification reform

[Jmapb]

On 5/20/2021 11:27 AM, Adam Franco wrote:

> I don't know Ithaca that well, but would NY-13 be an option for a sole
> upgrade? It would connect to I-81 and from there on to
> Syracus/Binghamton on the east end and points south/west via 86.
> As a reference point, NY-13 (and NY-79) are included in the NHS
> <https://www.fhwa.dot.gov/planning/national_highway_system/nhs_maps/new_york/ny_newyork.pdf>
> while NY-96 to Geneva and NY-34 to Auburn aren't.

By the proposal as written, NY-13 would certainly be tagged as trunk.
Some short segments of it already are. But other parts are two-lane
roads directly through villages, with stoplights and plenty of
residential driveways. In Dryden it takes a 90 degree turn at a
stoplight, switching between Main Street and North Street. This is far
enough from the current common usage of trunk in the US that it gives a
little pause. (Of course the definition of trunk is part of what's on
the table here.)

However, the way I read the text of the proposal ("the collection of all
highway=motorway + highway=trunk should comprise of the network of roads
on which a motorist would travel when transiting between any pair of
important population centers") we can't just send one trunk through
Ithaca and call it a day; we have to account for transit between any
pair of cities. So it sounds like NY-79 (currently secondary, passing
through villages and at least one stop sign) would also need to be
trunk, because a motorist driving from Ithaca to Binghamton would
generally use NY-79.

But things get murky when you want to go from Ithaca to Rochester. There
are several choices, and it's unclear which our motorist would choose.
The route that sticks to the most major roads would via NY-96, NY-96A,
US-20, NY-14 to I-90. Upgrading all this to trunk would include urban
blocks in downtown Geneva (12k, so presumably not an important
population center in its own right) ... But you probably wouldn't want
to detour through Geneva, you'd skirt via little roads like Serven and
Packwood https://osm.org/way/139892651 https://osm.org/way/20124537 ...
Or maybe you'd prefer to stay on NY-96 the whole way to the interstate,
which is reasonably direct but goes through more villages with
stoplights, 90 degree turns, low speed limits etc. And there are other
choices too -- NY-89 is an option, or straight up NY-34 to US-20, for
example. There just isn't a single obvious best way. And no matter where
I look, I don't see a trunk.

Maybe Ithaca's a good test case for minimum size to qualify for
"important population center". But it's not small -- the city is 30k and
metro area is 100k. Having trunk connections would make sense. But just
because it would make sense doesn't mean they're actually there.

Ultimately I think a rule saying that there *must* be at minimum a trunk
route between any two given cities, without paying any heed to the
physical nature of the roads between those cities, is problematic.


> The urban trunk guidelines probably need some tweaking, but the
> Manhattan grid is also a bit of a special case where there are many
> equally large parallel routes through the city grid. in both bridge
> cases they are extremely important connections between boroughs with
> more population than several states, so connections to motorways don't
> feel like a good exclusionary principle. In the Manhattan Bridge case
> I'd think it would make sense to upgrade Canal Street to trunk as it
> connects across the island to the Holland tunnel and does serve as a
> major through-traffic route.
>
> I'd want to look to local NYC mappers to make the call though on which
> streets in Manhattan are the most sensible to upgrade to trunk as an
> indication that this is the most direct and heavily used way through
> the city (if not necessarily /fastest/ in heavy traffic when bypassing
> on residential streets /may/ be a time-saving).

I'm not sold on the idea of using trunk instead of primary for the most
prominent surface roads in the urban grid. It seems like a major
departure from standard tagging practice and I don't see a lot to gain
by it.

But I could see an exception being made for Canal Street. Despite being
right in the densest part of the city, it carries a lot of intercity and
interstate traffic, including a fair amount of freight. And it connects
to trunks on both ends.

The downtown half of the West Side Highway (currently primary) might
also qualify. It's not really in the the grid per se though; it's
peripheral.

>     The proposed definition of primary also gives me pause vis-a-vis
>     NYC, in
>     particular the line"in a large enough city, surface streets with
>     an exit
>     from a motorway would likely qualify as primary." I see plenty of
>     examples of motorway exits onto secondary and tertiary streets. The
>     streets in question are not primary because they are *not* the most
>     prominent streets in the urban grid. (And there's probably some
>     sense in
>     dumping motorway traffic into places that don't clog up the major
>     arteries!)
>
>
> I agree -- this guidance on motorway exit connections should be
> revised as it may be unhelpful or counterproductive in many cases. Its
> applicability is likely dependent on historical development patterns.
>
>     Just to be clear, I don't think all of NYC's surface streets are
>     perfectly classified, but this kind of rule is going to hurt more than
>     it helps. We'd end up with lots of one-block-long primary highways,
>     which would trigger a ripple effect of upgrades to match comparative
>     prominence and to fix continuity errors.
>
>
> One-block upgrades don't go toward the larger goal of connectivity in
> the highway network at a given level and greater, so guidelines should
> be revised to be more easily applicable to reach toward the larger
> goal of connectivity rather than adhering to a rule for the sake of a
> rule. While I do visit every year, I'm not familiar enough with NYC to
> write guidelines for the boroughs. I'd think that the most important
> cross-borough and inter-borough routes would be motorway or trunk
> depending on their construction. Below that would be the next level of
> inter and intra-borough streets as primary. How might you identify
> that next level of streets?

The inter-boro roads are usually bridges and tunnels, and generally
they've been classified to match the highways or surface streets that
they connect. As for the surface streets, I tend to assign prominence
based on how useful a road is for a longish surface-level drive. There
are some telling physical characteristics -- road length and width,
two-way versus one-way, number of lanes, dual carriageways, turn lanes,
lights and stop signs. I'd be hard-pressed to codify these into a rule
system though.

I haven't dug into it, but I imagine that NYC's Department of
Transportation has its own road classification system, and if so it
might yield some insights. Personally I'm partial to "ground truth"
classification.

Jason

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