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Arizona DDI with strange ramp about to be built

Started by johndoe, January 19, 2019, 01:46:55 PM

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johndoe



One disadvantage of DDI is lack of "through" off-ramp movement, it looks like this Arizona proposal makes them go right and then left to get to the frontage roads.  However I'm not quite sure what's going on with the upper left on-ramp.  Is that a weave?  A braid?  A signal?

Here's another diagram but again I can't really tell: https://www.azdot.gov/projects/central-district-projects/i-17-ti-reconstruction-happy-valley-rd-and-pinnacle-peak-rd/happy-valley-road


1995hoo

Based on zooming in to see the ramp striping, it looks like they don't want people who've come from the bottom of the image who are heading to whatever that area at the top left is cutting across the traffic that's coming from the top of the image and bearing right onto the highway, so they're providing a separate movement. Wouldn't be surprised if there were pylons or something to discourage the cut-across maneuver. No idea why it's not the same as at the bottom right part of the image.
"You know, you never have a guaranteed spot until you have a spot guaranteed."
—Olaf Kolzig, as quoted in the Washington Times on March 28, 2003,
commenting on the Capitals clinching a playoff spot.

"That sounded stupid, didn't it?"
—Kolzig, to the same reporter a few seconds later.

NE2

pre-1945 Florida route log

I accept and respect your identity as long as it's not dumb shit like "identifying as a vaccinated attack helicopter".

jamess


froggie

^^^ It's not the same as the bottom right because the bottom right is a bona-fide frontage road that doesn't have immediate access back to I-17.  The upper left, as SPUI noted, is a bus stop with a direct connection to southbound 17.

They likely did it that way so that they'd only need one access from eastbound Happy Valley instead of two.

jeffandnicole

Quote from: jamess on January 21, 2019, 06:18:33 PM
What a horrific use of land

It takes up no more room than the existing interchange.

johndoe

Quote from: NE2 on January 19, 2019, 04:52:51 PM
It's a bus stop.
You're right, here it is in Google:
https://www.google.com/maps/@33.7089524,-112.1171462,39m/data=!3m1!1e3

I just assumed it was a frontage road, not a bus-specific road.  I'm not familiar with "bus on-ramp within a normal on-ramp"...you learn something every day!

jamess

Quote from: jeffandnicole on January 22, 2019, 08:03:32 AM
Quote from: jamess on January 21, 2019, 06:18:33 PM
What a horrific use of land

It takes up no more room than the existing interchange.

That doesnt change the validity of my statement

tradephoric

Quote from: jamess on January 22, 2019, 11:27:49 PM
Quote from: jeffandnicole on January 22, 2019, 08:03:32 AM
Quote from: jamess on January 21, 2019, 06:18:33 PM
What a horrific use of land

It takes up no more room than the existing interchange.

That doesnt change the validity of my statement

J&N is in a constant fog, blinded by the trees, and stuck in a forest.

abefroman329

Quote from: johndoe on January 22, 2019, 07:41:08 PMI'm not familiar with "bus on-ramp within a normal on-ramp"...you learn something every day!
Pretty common where you have park-and-ride lots served by commuter buses that use the expressway - I used to see them in the Atlanta area.

jeffandnicole

Quote from: tradephoric on January 23, 2019, 10:50:04 AM
Quote from: jamess on January 22, 2019, 11:27:49 PM
Quote from: jeffandnicole on January 22, 2019, 08:03:32 AM
Quote from: jamess on January 21, 2019, 06:18:33 PM
What a horrific use of land

It takes up no more room than the existing interchange.

That doesnt change the validity of my statement

J&N is in a constant fog, blinded by the trees, and stuck in a forest.

How so?  The interchange area really isn't all that large.  Heck - they're removing roundabouts...thought you would be excited about that.

Brandon

Quote from: jamess on January 22, 2019, 11:27:49 PM
Quote from: jeffandnicole on January 22, 2019, 08:03:32 AM
Quote from: jamess on January 21, 2019, 06:18:33 PM
What a horrific use of land

It takes up no more room than the existing interchange.

That doesn't change the validity of my statement

It does take up quite a bit of land when compared to the interchanges north and south of it.  From my point of view, I'd rather narrow the interchange and continue the service drives (note them north and south) through the interchange.
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tradephoric

Quote from: jeffandnicole on January 23, 2019, 11:31:16 AM
How so?  The interchange area really isn't all that large.  Heck - they're removing roundabouts...thought you would be excited about that.

I tried to find another service interchange in the Phoenix area with a larger footprint than that proposed DDI, and i was unable to find one.  Hell, it's larger than many freeway-to-freeway interchanges in the city.  Let's just agree that it's not a small footprint when it's one of the largest service interchanges in a metro area of 4.7 million people.

jamess

Quote from: tradephoric on January 23, 2019, 12:05:09 PM
Hell, it's larger than many freeway-to-freeway interchanges in the city.

Thats what I was thinking as well. It makes me wonder if that was the original or future plan for the area.

Or did someone at DOT have a brother-in-law that had a lot of land to sell...

abefroman329

I wonder if some of those darker lines hint at future uses for the land.

mapman1071

Quote from: abefroman329 on January 23, 2019, 11:28:56 AM
Quote from: johndoe on January 22, 2019, 07:41:08 PMI'm not familiar with "bus on-ramp within a normal on-ramp"...you learn something every day!
Pretty common where you have park-and-ride lots served by commuter buses that use the expressway - I used to see them in the Atlanta area.
See AZ51 Southbound onramps at Shea Blvd

jakeroot

#16
The biggest loss here will be the gorgeous British-spec roundabout signage. It's not the only roundabout interchange in Arizona with this style of signage, but it'll be one less, which is sad.

I don't think the chisel-point/stub arm map-type signs (1st and 3rd image) are too unusual in AZ, even today (certainly not as rare as their attempts at Australian map-type signs), but the lane-assignment signs are certainly quite rare. I've never seen such signs outsize Arizona, though I'm sure this is the result of Arizona's engineers pulling quite a few pages from Britain's signage manual over the years.







Aside from this, I agree that the proposal is a silly use of land. Lots of room for something far more creative.

cjw2001


kphoger

Keep right except to pass.  Yes.  You.
Visit scenic Orleans County, NY!
Male pronouns, please.

Quote from: Philip K. DickIf you can control the meaning of words, you can control the people who must use them.

cjw2001

Quote from: kphoger on January 25, 2019, 09:15:34 PM
Quote from: cjw2001 on January 25, 2019, 08:54:07 PM
Roundabout signage is pretty common in Carmel  https://www.google.com/maps/@39.9854494,-86.1405892,3a,26.5y,276.33h,92.81t/data=!3m6!1e1!3m4!1sYZsIGO5Eq13UUFwqbrlBSQ!2e0!7i13312!8i6656?hl=en

His post wasn't about roundabout signage in general, but rather British-spec (more or less) roundabout signage specifically.
And how does the link I shared differ much from the example he gave? 

jakeroot

Quote from: cjw2001 on January 25, 2019, 09:57:44 PM
Quote from: kphoger on January 25, 2019, 09:15:34 PM
Quote from: cjw2001 on January 25, 2019, 08:54:07 PM
Roundabout signage is pretty common in Carmel  https://www.google.com/maps/@39.9854494,-86.1405892,3a,26.5y,276.33h,92.81t/data=!3m6!1e1!3m4!1sYZsIGO5Eq13UUFwqbrlBSQ!2e0!7i13312!8i6656?hl=en

His post wasn't about roundabout signage in general, but rather British-spec (more or less) roundabout signage specifically.
And how does the link I shared differ much from the example he gave?

Your signs use normal arrows instead of the 90° chamfer arrows, a hallmark of British road signs. Also, the diagram does not show a line continuing past the last exit to indicate 'u-turn'. Lines are pretty thin too.

kphoger

Keep right except to pass.  Yes.  You.
Visit scenic Orleans County, NY!
Male pronouns, please.

Quote from: Philip K. DickIf you can control the meaning of words, you can control the people who must use them.

cjw2001

Quote from: jakeroot on January 25, 2019, 10:27:07 PM
Quote from: cjw2001 on January 25, 2019, 09:57:44 PM
Quote from: kphoger on January 25, 2019, 09:15:34 PM
Quote from: cjw2001 on January 25, 2019, 08:54:07 PM
Roundabout signage is pretty common in Carmel  https://www.google.com/maps/@39.9854494,-86.1405892,3a,26.5y,276.33h,92.81t/data=!3m6!1e1!3m4!1sYZsIGO5Eq13UUFwqbrlBSQ!2e0!7i13312!8i6656?hl=en

His post wasn't about roundabout signage in general, but rather British-spec (more or less) roundabout signage specifically.
And how does the link I shared differ much from the example he gave?

Your signs use normal arrows instead of the 90° chamfer arrows, a hallmark of British road signs. Also, the diagram does not show a line continuing past the last exit to indicate 'u-turn'. Lines are pretty thin too.

For this specific sign, U-turn not available to go the wrong way up a highway ramp.

To me the functional aspects are far more important than the arrow style and line width.

jakeroot

Quote from: cjw2001 on January 26, 2019, 02:29:39 PM
For this specific sign, U-turn not available to go the wrong way up a highway ramp.

To me the functional aspects are far more important than the arrow style and line width.

True, but standard Britisn design would still include an arrow to indicate the ability to continue past the last exit.

Nevertheless, "functionality" is not something that is relevant to my post. I'm referring completely to the design, which has British roots. Though, to be honest, I do prefer the British designs, as several of the signage components are larger and a bit simpler.



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