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National Boards => General Highway Talk => Topic started by: hbelkins on June 23, 2013, 01:46:38 PM

Title: "Multiplex?"
Post by: hbelkins on June 23, 2013, 01:46:38 PM
Does anyone know the origin of the term "multiplex" to describe two or more numbered highways running concurrently?

Myself, I hate that term. I prefer "concurrent" or some variation of that word, "co-signed," "routed together," "share pavement" or any number of other words or phrases.

Right: I-64 and I-75 run concurrently around the north and east sides of Lexington.
Right: US 60 and US 460 used to share pavement between Frankfort and Louisville before the latter was decommissioned.
Right: I-64 and I-77 are co-signed along the West Virginia Turnpike between Beckley and Charleston.

Wrong: US 23, US 119, US 460 and KY 80 are multiplexed through Pikeville and south to the Shelbiana area of Pike County.
Title: Re: "Multiplex?"
Post by: xonhulu on June 23, 2013, 02:04:54 PM
Quote from: hbelkins on June 23, 2013, 01:46:38 PM
Does anyone know the origin of the term "multiplex" to describe two or more numbered highways running concurrently?

Myself, I hate that term. I prefer "concurrent" or some variation of that word, "co-signed," "routed together," "share pavement" or any number of other words or phrases.

Right: I-64 and I-75 run concurrently around the north and east sides of Lexington.
Right: US 60 and US 460 used to share pavement between Frankfort and Louisville before the latter was decommissioned.
Right: I-64 and I-77 are co-signed along the West Virginia Turnpike between Beckley and Charleston.

Wrong: US 23, US 119, US 460 and KY 80 are multiplexed through Pikeville and south to the Shelbiana area of Pike County.

I agree with you on disliking "multiplex" or any of its variants, like "duplex" or "triplex."

My preference would be "co-signed," with or without the hyphen.
Title: Re: "Multiplex?"
Post by: NE2 on June 23, 2013, 02:21:19 PM
m.t.r.

"Overlap" sounds most natural to me. "Co-signed" doesn't work if the routes aren't signed.
Title: Re: "Multiplex?"
Post by: hbelkins on June 23, 2013, 03:27:51 PM
Quote from: NE2 on June 23, 2013, 02:21:19 PM
m.t.r.

I knew that, but I can't remember who coined the term.
Title: Re: "Multiplex?"
Post by: triplemultiplex on June 23, 2013, 06:36:04 PM
My opinion of it's use should be obvious.
:hmmm:

Might have something to do with growing up in an area where the movie theater only has one screen.  The more common definition is just not something in the lexicon of my past.  (You can go to the same building with people and see different movies?!)

I can always say it's a more technical word for "menage a trois".  :sombrero:
Title: Re: "Multiplex?"
Post by: english si on June 23, 2013, 07:01:02 PM
merger is (was) the official UK term - as shown in documents from before WW2. I've been using it on SABRE (and concurrent) for ages, but the rest SABRE keeps on using multiplex almost universally.  :banghead:
Title: Re: "Multiplex?"
Post by: Mapmikey on June 23, 2013, 07:53:49 PM
In older CTB documents Virginia has used the terms "overlay" and "concurrency"


Mapmikey
Title: Re: "Multiplex?"
Post by: J N Winkler on June 23, 2013, 08:17:35 PM
Multiplex is fundamentally an electrical engineering term and I remember it from my first days on MTR back in 2001.  As applied to route overlaps, it has always grated on me.  It implies a focus on routing at an abstract, topological level that not only fails to do justice to the historical, cultural, and scenic attributes of the road under discussion, but also is frequently not supported by the actual administrative detail of route designation.

This said, the electrical engineering definition of multiplex actually makes more sense than the movie-theater definition when applied to route overlaps.  The former usage is also older (Wikipedia suggests 1910 versus 1930's).
Title: Re: "Multiplex?"
Post by: ChoralScholar on June 23, 2013, 09:58:33 PM
I like multiplex because you can add other descriptors, like 'wrong-way multiplex' or 'unsigned multiplex'.  I'm not sure how you would describe those situations with the word 'concurrent' or some such.
Title: Re: "Multiplex?"
Post by: xonhulu on June 23, 2013, 10:22:24 PM
Quote from: ChoralScholar on June 23, 2013, 09:58:33 PM
I like multiplex because you can add other descriptors, like 'wrong-way multiplex' or 'unsigned multiplex'.  I'm not sure how you would describe those situations with the word 'concurrent' or some such.

"Wrong way concurrency" or "unsigned concurrency?"  Sounds o.k. to me.

For that matter, "wrong-way overlap/unsigned overlap" works, too.  Ditto with "overlay."

Unfortunately, my preferred term, "co-sign," doesn't lend itself to this:  "wrong-way co-signage" sounds awkward, and "unsigned co-signage" sounds moronic.
Title: Re: "Multiplex?"
Post by: Avalanchez71 on June 23, 2013, 10:23:59 PM
How about the concurrent multi-plex?  There is a famous one in Nashville where US 70 and US 70S are concurrently multi-plexed.
Title: Re: "Multiplex?"
Post by: Duke87 on June 23, 2013, 11:03:07 PM
As a kid the term I always used was "merge", e.g "route 73 and route 86 are merged for this section of road".

Since I actually started talking to other roadgeeks I've dropped this in favor of "multiplex" or "concurrency" since those are the terms people here commonly understand (to be fair "merge" with respect to roads can also mean something else unrelated, so it isn't a great term for this use).

"Multiplex" has the advantage of being one syllable less, so it makes extended terms like "wrong way multiplex" that much less of a mouthful. But in other situations I have no preference. 
Title: Re: "Multiplex?"
Post by: Scott5114 on June 24, 2013, 06:09:19 AM
I tend to use "concurrency" and "overlap", switching it up to whichever seems more appropriate. So I might say "the US-77/SH-39 concurrency" but "US-77 and SH-39 overlap through Purcell".

Multiplex seems to have fallen out of favor recently. One neat thing about "multiplex" is that you can specify the number of routes if you elect: duplex, triplex, quadruplex... etc.
Title: Re: "Multiplex?"
Post by: bugo on June 24, 2013, 10:24:41 AM
I hate it too.  I am guilty of saying "duplex" but i prefer "overlap" or a simple "route x/route xx".  Being from Arkansas, I like the term "piggyback".
Title: Re: "Multiplex?"
Post by: realjd on June 24, 2013, 04:46:31 PM
Multiplex is an old engineering term and has nothing to do with movie theaters. It's used to describe multiple signals being combined to travel across the same medium. Applying it to roads makes sense IMO.

http://en.wikipedia.org/wiki/Multiplexing
Title: Re: "Multiplex?"
Post by: Pete from Boston on June 24, 2013, 06:53:32 PM
Oldest reference I can find on Google is by one Bob Goudreau, 3/21/1997:

https://groups.google.com/d/msg/misc.transport.road/Uv0QHLoi1oI/B4ayAVLFTnQJ

"But if a northbound interstate (increasing numbers) happened to be
multiplexed onto a *westbound* interstate (decreasing numbers)..."
[/list]
Title: Re: "Multiplex?"
Post by: NE2 on June 24, 2013, 07:18:00 PM
I don't think the Goog's archive goes back before 1997.
Title: Re: "Multiplex?"
Post by: Alps on June 24, 2013, 08:35:51 PM
Quote from: Pete from Boston on June 24, 2013, 06:53:32 PM
Oldest reference I can find on Google is by one Bob Goudreau, 3/21/1997:

https://groups.google.com/d/msg/misc.transport.road/Uv0QHLoi1oI/B4ayAVLFTnQJ

    "But if a northbound interstate (increasing numbers) happened to be
    multiplexed onto a *westbound* interstate (decreasing numbers)..."
    [/list]

    "Multiplexed onto" vs. "multiplexed with", the latter of which is the current usage. The former is more in the engineering sense.
    Title: Re: "Multiplex?"
    Post by: Pete from Boston on June 24, 2013, 11:12:28 PM
    Quote from: NE2 on June 24, 2013, 07:18:00 PM
    I don't think the Goog's archive goes back before 1997.

    I wish it didn't.  I'd be spared facing the stupid things I said in college otherwise, but sasly they're there.
    Title: Re: "Multiplex?"
    Post by: NE2 on June 24, 2013, 11:40:55 PM
    Aha: http://groups.google.com/advanced_search
    Looks like m.t.r was created in December 1995.

    HB uses multiplex in response to a post by harry "bugo" sachz: https://groups.google.com/d/msg/misc.transport.road/iI9Ibxs-NPY/TIQmdy2qoLIJ

    This seems to be the first use (July 15, 1996), also by Bob Goudreau:
    https://groups.google.com/forum/#!topic/misc.transport.road/-BK863Z5o-s
    QuoteWell, sure, there are lots of places where two routes are multiplexed
    onto a single dual-signed roadway.  Where the routes diverged, one
    route often has to be accessed by an exit off the other.  Local
    examples for me include I-40/I-85 between Greensboro and Hillsboro:
    since the I-85 mileposts and exit numbers are used on this dual-signed
    stretch, you have to take a numbered exit to remain on I-40 in either
    direction.  Even closer to me is the I-440 Raleigh Beltline; the bottom
    half of this road is also I-40, so you have to exit in order to stay
    on 440.

    ----------------------------------------------------------------------
    Bob Goudreau                        Data General Corporation
    goud...@dg-rtp.dg.com                62 Alexander Drive       
    +1 919 248 6231                        Research Triangle Park, NC  27709, USA
    Sig included because it provides definite evidence of an adaptation of the network definition.
    Title: Re: "Multiplex?"
    Post by: froggie on June 25, 2013, 04:34:23 AM
    There's worse MTR adages than the term "multiplex".  "BGS", for one...
    Title: Re: "Multiplex?"
    Post by: Henry on June 25, 2013, 10:55:24 AM
    You know, I used to say multiplex quite a lot, especially back when I first became an Internet regular, but I see that there are some better terms out there; concurrency and overlap are my top two. However, I hate the term duplex; it makes me think of a large house that's literally divided into two smaller ones.
    Title: Re: "Multiplex?"
    Post by: Pete from Boston on June 25, 2013, 12:39:22 PM
    Quote from: froggie on June 25, 2013, 04:34:23 AM
    There's worse MTR adages than the term "multiplex".  "BGS", for one...

    Is "button copy" an MTRism?
    Title: Re: "Multiplex?"
    Post by: agentsteel53 on June 25, 2013, 12:59:16 PM
    Quote from: Pete from Boston on June 25, 2013, 12:39:22 PM
    Is "button copy" an MTRism?

    nope.  I have Caltrans references as old as 1978 which refer to "reflector button copy" and "button copy".  I probably have older; just don't have my files organized as well as I would like.
    Title: Re: "Multiplex?"
    Post by: NE2 on June 25, 2013, 01:16:04 PM
    Quote from: froggie on June 25, 2013, 04:34:23 AM
    There's worse MTR adages than the term "multiplex".  "BGS", for one...
    On the other hand, 'big green sign' works well when talking to a non-roadgeek.
    Title: Re: "Multiplex?"
    Post by: kphoger on June 25, 2013, 02:41:25 PM
    "BGS" was met with blank stares when I used it among highway engineers, though.  They had some crazy, official-sounding, multi-word term for a BGS (which they only vaguely remembered, by the way).  What losers.
    Title: Re: "Multiplex?"
    Post by: NE2 on June 25, 2013, 03:25:45 PM
    Whatever. "Guide sign" is a precise enough replacement, and "big green sign" when talking to the unwashed masses.
    Title: Re: "Multiplex?"
    Post by: hbelkins on June 26, 2013, 12:17:58 AM
    I have used "multiplex" in the past but the term began grating on me in later years.

    Our engineers use the term "panel signs" to refer to guide signs or "big green signs."
    Title: Re: "Multiplex?"
    Post by: J N Winkler on June 26, 2013, 10:54:25 AM
    To add to Jake's comments regarding button copy--I am sure I have seen reflective button letters (or similar phrasing) in Caltrans documentation.  AGA letters and AGA copy have also been used (the American Gas Accumulator Co., which was subsequently absorbed into Stimsonite, was the leading manufacturer of framed button copy).

    To add to NE2's comments about big green sign:  the full phrase is indeed readily understandable by non-enthusiasts (though big is a decidedly non-U word), but the acronym is not.  I usually use the phrase large guide sign when I wish to refer to guide signs that are sufficiently large in format to be used on freeways or expressways, and D-series sign when I want to refer to smaller guide signs that are used on conventional roads (i.e., any public road that is not a freeway, expressway, or some other type of special-purpose facility).  D-series signs get their name from the fact that the MUTCD sign codes for them start with D.

    To add to what H.B. and Kphoger say about BGS, the actual terminology used by most state DOTs is generally based on substrate type.  In Kentucky, for example, panel sign can be taken to mean "large guide sign" because KyTC uses sheet aluminum for typical D-series applications.  That approach would not work in other states like California and Washington, because the full panoply of substrate types is used for both conventional-road and freeway/expressway applications.  Other state DOTs talk in terms of type classification--"Type A," "Type B," etc. in many states, or even "Type I," "Type II," "Type III," etc. in Michigan--which are generally composite references to substrate type, sign sheeting type, or even mounting position (overhead versus ground-mounted).  The cutoffs between the types are based on how standard bid items are defined.  (Most state DOTs ask contractors bidding on signing work to quote a unit price of so many dollars per square foot for quantities that are expressed as total square feet of a given sign type.  The only exception I am aware of is Florida DOT, which has separate bid quantities for various sign types by square foot range, and asks contractors to quote on a "per each" basis:  so many signs with sizes ranging from 60 to 80 SF, so many signs with sizes ranging from 80 SF to 100 SF, etc.)

    In Kansas the phrase "High performance sheeting" is, rather oddly, usually a clue that small signs (including D-series signs) are being talked about, since KDOT tends to avoid that phrase in bid items for large guide signs (even though it is my understanding that the same type of sheeting is used for them).
    Title: Re: "Multiplex?"
    Post by: agentsteel53 on June 26, 2013, 12:37:12 PM
    Quote from: J N Winkler on June 26, 2013, 10:54:25 AM
    D-series signs get their name from the fact that the MUTCD sign codes for them start with D.

    here I always thought you called them that because an older spec of them had Series D all-caps letters.

    interestingly, the old old internal reference code for such a sign in California - dating back to 1934 - is D as well.  not the specification sheet, which has them as a subset of the G-series, but the actual stamp on the back.  D10D181 is a sign that just appeared on eBay.  1937, district 10, "direction or distance", serial number 181.