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Boring interchanges

Started by webny99, May 19, 2017, 12:05:16 AM

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hotdogPi

Quote from: ColossalBlocks on May 20, 2017, 01:42:52 PM
Quote from: webny99 on May 20, 2017, 10:58:09 AM
Quote from: ColossalBlocks on May 19, 2017, 03:54:44 PM
So, basically every stack, diamond, cloverleaf, trumpet, and DDI ever built in the country and/or world.

Not sure what this means... you're saying those do or don't qualify?
Obviously, this is a fairly subjective topic, but there are very interesting examples of all of those interchange types...

Yes, they do qualify for being boring.

How are DDIs boring?
Clinched, minus I-93 (I'm missing a few miles and my file is incorrect)

Traveled, plus US 13, 44, and 50, and several state routes

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plain

Quote from: webny99 on May 22, 2017, 05:06:17 PM
Quote from: 7/8 on May 19, 2017, 09:47:08 AM
For Ontario, I would argue that the Parclo A4 is the dominant (and therefore boring) interchange type.

I'd agree with that argument. I've often wondered why that is, given that many rural interchanges also have that setup (somewhat unnecessarily IMO). It certainly wouldn't be more cost-effective than a simple diamond... any insight?

I was wondering about that myself as a standard diamond should be the obvious choice for a rural interchange. No need to waste $$$ for something that isn't necessary.

I do know why a parclo would be superior to a full clover for busier interchanges though as it eliminates weaving on the freeway aspect of the interchange, but again I think it's totally unnecessary for ones that are not busy at all.
Newark born, Richmond bred

7/8

Quote from: plain on May 22, 2017, 05:48:07 PM
Quote from: webny99 on May 22, 2017, 05:06:17 PM
Quote from: 7/8 on May 19, 2017, 09:47:08 AM
For Ontario, I would argue that the Parclo A4 is the dominant (and therefore boring) interchange type.

I'd agree with that argument. I've often wondered why that is, given that many rural interchanges also have that setup (somewhat unnecessarily IMO). It certainly wouldn't be more cost-effective than a simple diamond... any insight?

I was wondering about that myself as a standard diamond should be the obvious choice for a rural interchange. No need to waste $$$ for something that isn't necessary.

I do know why a parclo would be superior to a full clover for busier interchanges though as it eliminates weaving on the freeway aspect of the interchange, but again I think it's totally unnecessary for ones that are not busy at all.

From quickly scanning Google Maps, it seems like rural interchanges on the 401 are often parclo A2's. One advantage I can see with these are that they are easy to upgrade to A4's if traffic counts ever increase. Since A2's and Diamonds both have 4 ramps, I would assume the costs are also comparable.

I guess I should change my original comment to Parclos in general as being dominant in Ontario.

I-90


7/8

Quote from: I-90 on May 22, 2017, 06:02:30 PM


Do you think DDI's are boring? I've never even driven one :-D! It pains me that I drove on US 65 by Springfield, MO and found out a month later that there's a DDI there :-(.

By the way, what interchange is in that photo (just curious)?

I-90


ilpt4u

#31
I've driven on 2 Illinois DDIs, one up North and one way down South

Northern IL: I-88/Reagan Tollway and IL-59 (Exit 123)

Southern IL: I-57 and The Hill Ave (Exit 54B)

I think those were the first 2 in IL? I could be mistaken. There are probably more by now, I think

And I don't think they are that boring, as they are still relatively Unique. Tho I am annoyed when you take the exit and make the "Left" turn movement, when the driver ahead of you won't make the Legal and Available Left-on-Red maneuver -- usually a quick horn toot solves the problem

7/8

Quote from: webny99 on May 22, 2017, 11:29:34 PM
Quote from: 7/8 on May 22, 2017, 05:57:12 PM
From quickly scanning Google Maps, it seems like rural interchanges on the 401 are often parclo A2's. One advantage I can see with these are that they are easy to upgrade to A4's if traffic counts ever increase. Since A2's and Diamonds both have 4 ramps, I would assume the costs are also comparable.

I guess I should change my original comment to Parclos in general as being dominant in Ontario.

I was actually thinking of the QEW between the falls and Burlington, but perhaps that area doesn't qualify as "rural"  :D
Are parclo A2's basically folded diamonds or am I missing something?

The QEW has some rural stretches, but not as much as some other 400-series highways. The most rural stretch of the QEW is between Niagara Falls and Fort Erie, and most of the interchanges are A4's :hmm:

Here's an A4 diagram


Here's an A2 diagram


And here's a folded diamond (very similar to the A2)


The folded diamond would be used over an A2 in Ontario if there are obstacles (such as properties, nearby waterway or uneven ground) in the left-two quadrants.

paulthemapguy

Quote from: ilpt4u on May 22, 2017, 08:44:21 PM
I've driven on 2 Illinois DDIs, one up North and one way down South

Northern IL: I-88/Reagan Tollway and IL-59 (Exit 123)

Southern IL: I-57 and The Hill Ave (Exit 54B)

I think those were the first 2 in IL? I could be mistaken. There are probably more by now, I think

And I don't think they are that boring, as they are still relatively Unique. Tho I am annoyed when you take the exit and make the "Left" turn movement, when the driver ahead of you won't make the Legal and Available Left-on-Red maneuver -- usually a quick horn toot solves the problem

I think those are indeed the first two.  I-90 at Elmhurst Road is under construction, and I-55 at Weber Road is coming soon.

DDI's are exciting though!  What's not exciting about the constant threat of someone failing to understand the counterintuitive positioning of the lanes and crashing head-on to an oncoming car?

Traffic safety probably isn't the realm for discussing what's boring, though, because we need roadway systems and alignments to be predictable, and therefore, boring, in order to promote safety.  We want things to be drab and easy to understand so that people don't get hurt...heh
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