Clinched Highway Mapping

froggie · Posted: Tue Jan 06, 2009 9:26 pm Post subject: AL: ALT US 78

Okay, here's the deal with this one.

I went back through AASHTO route committee notes and found where the two segments of ALT US 78 were approved.

But here's where the other shoe drops. ALDOT maps only show the western segment (west of Jasper) as being ALT US 78. And NEITHER section is signed as ALT US 78. West of Jasper is signed as AL 118. East of Jasper is still signed as US 78, as is the new segment of Corridor X between Jasper and Graysville.

I've sent an E-mail to ALDOT for clarification. But finishing the Alabama U.S. routes (and corrections) will have to wait until I hear back from them.
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admin · Posted: Tue Jan 06, 2009 10:44 pm Post subject:

With no further information, I'd proceed this way:

Include the Alt 78 route that appears on the official map.
Exclude the Alt 78 route that does not.
The "completion" of the Alabama US highways doesn't need to wait for this clarification, if this would end up being the only thing delaying making the US highways "go live".

Similarly, I made a file for Business US 40 in Brownsville, PA. AASHTO gave the approval. PennDOT hasn't signed it or mapped it. I'm excluding it from the project until one of those actions occurs.

oxlahun · Joined: 28 Jul 2008 Posts: 314 Location: Easthampton MA

rickmastfan67 · Joined: 14 Jul 2008 Posts: 2031 Location: Pittsburgh, PA

yakra · Joined: 30 Jul 2008 Posts: 2600 Location: Area Code 207

At risk of splitting off into a new topic...

This discussion makes me wonder about what routes to include, when...
I don't think we've developed any standards or conventions on what to include, and applied them consistently.

There are a few sources of info as to whether/where a route exists, including:
* signage in the field.
* State DOTs.
* AASHTO.
And it doesn't help that even some of these sources can be ambiguous or inconclusive, forcing us to make a best guess.

There are some highways that all sources can agree exist, eg ME US1AltPor
and some that all sources agree don't exist, eg ME US1Bus in Freeport.

Between these 2 obvious cases, we have some grey areas...
110: Recognized by AASHTO & State DOT, but not signed in the field. Eg ME I-495. (So, we have precedent in the project for including unsigned routes, in the secret interstates.)
001: Not recognized by AASHTO or State DOT, but signed in the field. I can't think of any examples offhand, but aren't there (interstate?) business loops maintained by a local municipality, signed in the field?
101: Recognized by AASHTO but not State DOT; signed in the field. I don't know of any existing, but it's not impossible that such a beast could exist.
011: No AASHTO; yes state DOT & field. Such as ME US1AltRoc, which is missing from the 1989 route log.
100: Not signed in the field or recognized by the state, but still recognized by AASHTO. This was why I still included IA US34BusGle - it was never deleted with AASHTO. So by this logic, both 78Alts could be included. (Or that hole in US51 ;D )
010: Not recognized by AASHTO or signed in the field, but still in state logs. Other than AASHTO, and the right shield in the field most of the time, what makes a US route a US route? Maybe still being shown on internal/planning maps with a US shield? ME US1AltBusBan, well... that's a further discussion that would just bog down this post.

So... when sources of info disagree on where a route goes, I go for a best-2-of-3 approach, with maybe a slight bias toward field signage.

When there's some disagreement on whether a route (or segment thereof, eg ME US202 I-395(2) US2) exists, I like to go with whatever will allow us to clinch more stuff in the project. =) Hence IA US34BusGle, or OK US62TmpLaw (which was never deleted with AASHTO after the final alignment was completed). And again, by my criteria I would include both 78Alts, US40Bus and US220Alt (What's the status of 220Alt with AASHTO now?)

I'm interested in hearing people's thoughts (Tim's especially) on when/what routes should be included, how we decide to include them, and what criteria may be good to decide whether to include routes in the project.

admin · Posted: Wed Jan 07, 2009 8:59 pm Post subject:

I'd say no. Sure it's another gray area with conflicting info. There are indications that Alt US 220 was intended only as a temporary designation and that it's supposed to now be obsolete.

yakra · Joined: 30 Jul 2008 Posts: 2600 Location: Area Code 207

By that argument we should definitely get rid of OK US62TmpLaw. =)

What criteria do you use determine whether to include a route? Or would you use to sort out more AASHTO/State/Field conflicts as they continue to crop up?

andytom · Joined: 14 Jul 2008 Posts: 412 Location: Beaverton, OR