Tennessee State Highways (usatn)

[wphiii]

I apologize if it's a gross breach in protocol to post this thread in this sub-forum, but I wasn't sure really where else it would belong. The Tennessee State Highway system is one of the systems that I've been awaiting most eagerly, but it doesn't appear that any work has been done for it.

I'd love to be able to help this project what little I can by doing some of the "grunt work" involved in plotting points for the routes, etc. From clicking around on GitHub I think I've got the gist of the format. I don't really know anything about the .wpt extension, but at the very very least I can work up the data in plain text if that's the most appropriate first step to do (unless there's some quick-and-dirty way to convert plain text to .wpt that I could do myself).

So, is the usatn system indeed completely virgin? If so, could I start working up files for those roads, and is there anything additional I'd need to know to begin doing so? Is there a better resource for these roads than Google Maps/Wikipedia? Is trying to bring a relative noob into this process more trouble than it's worth? I'll hang up and listen.

- Will

[mapcat]

Thanks for offering. Since Tennessee is one of James's (rickmastfan67) states, I suspect he will be taking the lead on this. He's currently working his way through the Florida state roads, however, and hasn't expressed when he might be ready to start work on the Tennessee highways as far as I know.


Please stick around and follow the conversations here to see when/if there will be an opportunity to begin on this, or at least help in other ways.

[yakra]

I don't really know anything about the .wpt extension, but at the very very least I can work up the data in plain text if that's the most appropriate first step to do (unless there's some quick-and-dirty way to convert plain text to .wpt that I could do myself).

The .wpt format is very simple. It's nothing more than plain text -- plain text files that happen to use the .wpt extension.

So, is the usatn system indeed completely virgin?

Apart from the routes already live in usansf / United States Select Numbered State Freeways (which would be migrated over to usatn once complete), I believe it is.

Correct me if I'm way off base here, but ISTR that TN has primary and secondary routes, with different shield styles for each, and that a single route number can flip-flop mid-route between primary & secondary status, with the corresponding changes in shield style. Kinda like (*groan*) Vermont, only a Much Bigger Deal, and much more pervasive. This would be a big complicating factor to sort out before work begins.

These few comments aside, I'll also hang up and wait for rickmastfan67's response.

[Duke87]

Correct me if I'm way off base here, but ISTR that TN has primary and secondary routes, with different shield styles for each, and that a single route number can flip-flop mid-route between primary & secondary status, with the corresponding changes in shield style. Kinda like (*groan*) Vermont, only a Much Bigger Deal, and much more pervasive. This would be a big complicating factor to sort out before work begins.

This is pretty accurate. Like with Vermont, the same highway can change between primary and secondary status, potentially multiple times. Like with Vermont, this distinction has only existed for the past 20-25 years or so when the current primary shield was implemented, all routes used to carry what now is the secondary shield.

Unlike with Vermont, the shield shape does not denote different maintenance responsibility. And while Vermont only has some "secondary" routes here and there, in Tennessee they're all over the place. It's a huge mess.

It would seem to me that the simplest way to handle this would be to ignore the distinction and just swallow the entire primary/secondary system in one gulp. On the other hand, there is some precedent in existing data hinting at handling the secondary routes separately - if you look at the waypoints for US highways in Tennessee, they are named in the format "TN##" for primary routes but "TNs##" for secondary routes. If we combine the primary and secondary systems, it might make sense to change the names of all these points accordingly.

[oscar]

There was some discussion somewhere on the aaroads forum (sorry, no time to look it up right now) about the abolition of the primary/secondary distinction in TN, even though there were plenty of secondary route markers still out there last time I was there last month. That would support Duke87's suggestion.

As for naming US route waypoints all as TNxxx (no TNsYYY), that's consistent with what we did with waypoints on the TCH routes in Canada's prairie provinces. which are all ABxxx, SKxxx, and MBxxx, even though all three provinces have different route markers for what was once the primary and secondary systems in AB, and still are similar systems in the other provinces. But rickmastfan67 is still following that distinction in Ontario, and might prefer to do likewise in TN.

[rickmastfan67]

Thanks for offering. Since Tennessee is one of James's (rickmastfan67) states, I suspect he will be taking the lead on this. He's currently working his way through the Florida state roads, however, and hasn't expressed when he might be ready to start work on the Tennessee highways as far as I know.

I have no problem if somebody else wants to do the state routes for TN.  I just need to finish overhauling US-64 first up to the current standards.  That's the last highway in the state that is pretty much lacking shaping points.

There was some discussion somewhere on the aaroads forum (sorry, no time to look it up right now) about the abolition of the primary/secondary distinction in TN, even though there were plenty of secondary route markers still out there last time I was there last month. That would support Duke87's suggestion.

I hadn't heard anything about that yet.  If that's the case and they are all to be considered as 'one' system in the eyes of TN, I would support converting all the 'TNs###' points to 'TN###', but not until it's official.

As for naming US route waypoints all as TNxxx (no TNsYYY), that's consistent with what we did with waypoints on the TCH routes in Canada's prairie provinces. which are all ABxxx, SKxxx, and MBxxx, even though all three provinces have different route markers for what was once the primary and secondary systems in AB, and still are similar systems in the other provinces. But rickmastfan67 is still following that distinction in Ontario, and might prefer to do likewise in TN.

As for the origins of the 'TNs###' naming style, Tim was on board for it when we were creating the original US Highways files.  It was also one of the early states to be done, well before Ontario was even started on, and same with the other Canadian provinces.

[mapcat]

James offered to let me draft usatn, and so I look forward to getting started over Christmas break.

Before I dive in, there are two issues worth discussing: how to handle the primary/secondary division of these routes, and how to deal with unsigned state highways that follow US highways.

There are varying descriptions of the meaning and status of the different classifications:

From AAroads's "Tennessee Gateway":

About the Tennessee Route System
State Routes in Tennessee were previously separated into secondary and primary routes. The differences were denoted by separate shield styles, with primary routes in rectangles and secondary routes in triangles. The two-tier system was derived from the Federal-Aid Primary and Federal Aid Secondary system of roads. That system was replaced with the National Highway System (NHS) in 1993, as part of the 1991 Intermodal Surface Transportation Efficiency Act (ISTEA). A de facto primary and secondary system still exists today, though the distinction is based upon importance versus funding/maintenance.

This 2016 NHS map shows that not all routes that use the primary shield are NHS routes. However, this AAroads forum post asserts that there is simply one system (albeit without citing any official source). The quote in the first post refers to the distinction disappearing on the official map in 2007, although it actually disappeared in 2004 (I checked the ones in my collection). Since then, the official state highway map has shown both classifications separately, with distinct shields for each, but refers to both in the legend as "Tennessee State Routes". TDOT county maps seem to agree with the classification split (although they classify both as "State Highways").

Personally I'd prefer to treat usatn as a single system, without differentiating between highways with different markers.

The other question is how to deal with the hidden state highways that follow the US highways. In general, we've been ignoring those, right? These mile markers (US 70 mile 5 in Carroll County) wouldn't change anyone's mind, would they? How about these new signs? One drawback to ignoring them is that their signed segments will exist as separate files. TN 1 is signed where it doesn't follow US highways in at least two places.

Personally I'd prefer to ignore the unsigned segments and create the extra files.

What does everyone else think?

[oscar]

The other question is how to deal with the hidden state highways that follow the US highways. In general, we've been ignoring those, right? These mile markers (US 70 mile 5 in Carroll County) wouldn't change anyone's mind, would they? How about these new signs? One drawback to ignoring them is that their signed segments will exist as separate files. TN 1 is signed where it doesn't follow US highways in at least two places.

Personally I'd prefer to ignore the unsigned segments and create the extra files.

What does everyone else think?

Sounds like a common situation in California, where legislatively route segments connected by other routes are defined separately without including the connecting multiplexes. Sometimes the multiplexes are signed, some not. Whether they are or not, I've included "implied concurrences" in routes. The only fragmented routes are due to never-built connections (such as where the Sierra Nevadas get in the way), or less often decommissioned (as with the permanent closure to the general public in the middle of CA 173).

[si404]

I'd argue play it by ear - if you are crafting the system, then you will get a good feel for what is and what isn't a valid implied concurrency (and if people disagree with your choice, they can say so).

Obviously [END] plates break a route up (cf some usain routes). I felt that implied concurrencies that were 'lengthy', especially ones that changed what the route was 'concurrent' with, broke gbna roads, such as A5, A34 and A41, but that roads ending at the bypass on one side of town and re-emerging at the other despite the section of bypass having two numbers wasn't a route-breaker

As much as it would be so much easier to map if every route was logical, fully signed, etc, the real world isn't like that - which also provides roadgeeks a lot of stuff to talk about.

[the_spui_ninja]

Personally I'd prefer to treat usatn as a single system, without differentiating between highways with different markers.

Well, for what it's worth, I think this makes sense, as it looks like some routes change back and forth between designs while still being continuous.

[bejacob]

There are a couple questions here.

As to the primary/secondary route split, I'm in favor of having one system for the state. It appears that some routes may be designated as primary in one are secondary in another despite being the same route (route 1 runs from Memphis to Bristol and changes back and forth, frequently running concurrently with US routes 64, 79, and 70 with many sections unsigned).

I'd also prefer to see each route as one file despite the unsigned sections along the concurrences. I suspect the number of routes will multiply quickly when breaking each route down for only the signed portions. Now if there really is a separation (like I-24 near Chattanooga where it dips into GA), not just an unsigned section, then breaking the route makes sense. Beyond that, I think one route, one file is better.

[froggie]

I suspect the number of routes will multiply quickly when breaking each route down for only the signed portions.

Not as much as you might expect.  Most (and there aren't that many) of the cases where a mixed route is signed are cases where it's overlying US route got rerouted (usually due to a bypass), and the old route was retained as a state highway but not with a bannered US route.

I'm with Mapcat in this case...ignore the hidden routes.  This will also be a necessary consideration for when the Alabama state routes are created.

Regarding primary/secondary and one system or two, we've had a similar issue with Vermont and there's precedent there with considering it all a single system, especially considering the routes that go back and forth between primary and secondary.

[yakra]

From the descriptions seen here, I'm also on board with a single system.
I agree with froggie on Vermont. (It's not a 1:1 comparison, but still a similar situation.)

I'm not well enough informed to have an opinion on the signed/unsigned issue.

[bejacob]

From the descriptions seen here, I'm also on board with a single system.

That part seems to have almost universal agreement. I'm sure there will be more comments, but the trends looks pretty clear.

I'm not well enough informed to have an opinion on the signed/unsigned issue.

I, too, will defer to others on this issue. While I like the idea of "one route, one file," it's not something I feel strongly about. It will be good to get these routes in the system, and whichever way they are set up, I look forward to filling in some gaps on my map between the Interstates and US highways.

[mapmikey]

I also believe one system is the way to go.

As for state routes that are hidden.  If the trend is for Tennessee to post the mile markers like this relatively new marker on US 72/TN 86 near the Mississippi border linked below, than it might be enough to say they are posted.  Even at the current size mile marker, the state number can be seen at highway speeds.  So unless Tennessee is phasing this style of mile marker out, I would have no problem including the hidden ones...

https://goo.gl/maps/kyZPQHce2MN2