<div dir="ltr"><div dir="ltr">On Mon, May 24, 2021 at 7:35 PM Jmapb <<a href="mailto:jmapb@gmx.com">jmapb@gmx.com</a>> wrote:<br></div><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
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<p>Thanks Kevin, you've really got the magic touch when it comes
extracting data from NY State. <br>
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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.)<br></p></div></blockquote><div><br></div><div>You're right. There's a classification that I'm missing that I think would be significant for OSM - 'principal arterial freeway' - which I misclassified as 'trunk road'.</div><div><br></div><div>These are freeways that are not all that significant for interurban routing because they don't carry significant traffic that doesn't originate or terminate in the metro area. At low zoom levels (z5-z6, maybe z7) they'd just clutter the map; you wouldn't be able to read them.</div><div><br></div><div>There's also a lot of red because here in the US we've been classifying roads a lot lower than most other places; insisting that a trunk has to be an 'almost freeway' or that a state highway can be at best secondary, things like that, rather than considering network connectivity.</div><div><br></div><div>I've been delving a little deeper into the data and patching it up some. <a href="https://kbk.is-a-geek.net/attachments/20210524/NY-class-1-2-3.png">https://kbk.is-a-geek.net/attachments/20210524/NY-class-1-2-3.png</a> is a replaement image, with blue showing the interurban motorways, purple the suburban motorways, red the proposed trunks, and black the proposed primary roads (which antialiasing is actually fading to grey). Note that not all state highways are primary! There are a lot of spots that would need local fixup - there are some obvious data entry errors, some routing islands, and some impedance mismatches at the urban/rural boundary, but I think this is a useful first approximation. <br></div><div><br></div><div>To see 'interurban' vs 'suburban' motorways clearer in the NYC area, I also produced <a href="https://kbk.is-a-geek.net/attachments/20210524/NYC-class-1-2-3.png">https://kbk.is-a-geek.net/attachments/20210524/NYC-class-1-2-3.png</a></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div><p>
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.<br>
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I fear we will, as you describe, end up with 50 to 56 different
wiki pages of highway tagging guidelines. So be it...<br></p></div></blockquote><div>The roads that you say are oversold, well, I presume that the state had some reason for classifying them the way they did. The loop on NY-12 and NY-23 from Binghamton to Oneonta is mysterious. Maybe to connect Binghamton and Oneonta with Utica? (No, I'll stick with 'mysterious.')</div><div><br></div><div>We're actually using a combination of features that the Federal road classification system tabulates fairly well, so I'm guessing that it'll work in some other states. The only problem is that so far we're applying them to states that tend to build roads that are fairly coherent. I dread trying to sort out Oklahoma or MIssissippi. <br></div><div><br></div><div>By the way, this classification would guide (a) what roads should appear at what zoom level and (b) routing preference for long-distance routings where an exact search for the best route would take too long. Rendering in a US map style should be based mostly on physical characteristics (grade-separated carriageways? All crossings elevated? Number of lanes? Speed limit?) and fall back on classification only as a last resort if the other characteristics are not mapped. That would allow us to bring in a two-lane trunk road such as US 209 south of Newburgh at a fairly small scale, but still show it as the relatively slow and narrow surface street that it is. (It just beats most of the alternatives to get to the Shawangunks and the Delaware Valley from, say Albany. There ain't no graceful way. There's a mountain range in the way.)</div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div><blockquote type="cite"><div dir="ltr">
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</blockquote></div>None of this would work as a mechanical edit, think of it as an AI-assisted one if you will. The data analysis emits a set of 'things to look at', human mappers look at them.<div><div><br></div>-- <br><div dir="ltr" class="gmail_signature">73 de ke9tv/2, Kevin</div></div></div>