Huge Interchanges

[froggie]

Agree that "soon" is relative.  But at least in that case, it's in-progress.

[Riverside Frwy]

An 8 level stack would be absolutely insane, not to mention expensive.The flyovers would be incredible, and the exit to the interchange would have to be WAY back in order to have enough room for the flyover to climb to the appropriate height to make it over the stack, especially for the higher levels.In fact, your ears would probably pop at the very top.

EDIT:Also, more than likely the HOV lanes would take the higher levels as trucks couldn't handle the higher levels, and since trucks can't go on HOV lanes anyway...

[andytom]

Actually, a full HOV stack in a full GP stack wouldn't have 8 levels.  First the mainline HOV lanes would stay with the mainline GP lanes (2 levels gone).  It would also not be too difficult to glom the HOV left turn ramps onto the GP left turn ramps.  So the only one that would need to have a separate level would be the HOV right turn ramps.

--Andy

[Bickendan]

That gets away with a 5-level stack? Not bad. That actually may make such a monster doable.

Here're my takes on monster interchanges... From west to east (north to south) on the same highway (I-510):

Line casings were turned off in all cases, as proper stack order never got completely defined correctly.

http://bickenland.lonaf.com/Maps/I-110_510.gif
I-110 runs southwest-northeast, I-510 runs more or less due north-south here.
The northeast-bound HOV/express carriageway on I-110 got borked by ArcGIS at some point, hence some of the ramps not connecting to anything. Orange lines are tunnels.

http://bickenland.lonaf.com/Maps/I-10_510.gif
I-10 runs west-east, I-510 north-south. 9-level stack, with a spui thrown in on I-510 at the artery just south of I-10.

http://bickenland.lonaf.com/Maps/I-93_95_510.gif
This one's a monster and would be breathtaking to drive through. I-93 begins at the interchange, runs north with a series of braided ramps that dissolve into a C/D system. I-95 comes in from the south and hooks back to the southeast. I-510 runs northwest-southeast and through the interchange duplexing with I-95. To quickly clarify some of the stack order: the westbound I-95 mainline (the thicker red line turning through the interchange) is groundlevel; the HOV/Express line making the same movement is at the top of the stack and everything else is in between.

http://bickenland.lonaf.com/Maps/I-95_195_510_595.gif
I-95 and I-510 come in from the west; I-95 goes north at the interchange and I-510 continues east and back south. The HOV/Express lines follow I-95 -- connector ramps from the bridge to the I-510 mainlines are missing (ArcGIS ate them, I guess). I-195 terminates at the main interchange, coming in from the south. I-595 begins at the eastern interchange, runs north. Braiding, C/Ds, surface highways joining in on the fun galore. TH 5 (blue and green US shield for reference; 'Tiaman Highway') runs from the southwest across the river, then north at the intersection (may be revised to a roundabout). I can't recall the numbers I assigned to the other routes, but ZH 172 comes to mind.

A couple notes for this fictional city: I-510 is a west-east route and functions as a transcontinental 2di, often as a toll-express route for I-10. 3dis don't adhere to the 'evens bypass, odds spur' rule, though it is observed. I-1xx is just as likely to be used as a beltway as I-6xx and vice-versa.

[J N Winkler]

An 8 level stack would be absolutely insane, not to mention expensive.  The flyovers would be incredible, and the exit to the interchange would have to be WAY back in order to have enough room for the flyover to climb to the appropriate height to make it over the stack, especially for the higher levels.  In fact, your ears would probably pop at the very top.

These observations about the altitude of ramps at the top level do not apply if several levels are underground, in tunnel--this has been done with at least one of the I-105 stacks and also the M-40/AP-1 stack near Madrid.

BTW, is there a particular reason why you are not inserting spaces after each period?  I don't mean to sound critical, but the lack of spaces does not make it easy to see where one sentence ends and the next begins.

[froggie]

Here it is...the full GP/HOV stack they're building at I-95/695.  Effectively 4 levels.

[Bickendan]

Ah, nice! That gives a nice working model for my I-10/510 interchange and fixes mine to a 5-level model.

[TheStranger]

Here's one that takes up a bit of land area, the modified cloverstack at TN 840 and I-65 in Harpeth, TN:

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Nashville&sll=38.567863,-121.439904&sspn=0.095562,0.144024&ie=UTF8&hq=&hnear=Nashville,+Davidson,+Tennessee&ll=35.822233,-86.834264&spn=0.024776,0.036006&t=h&z=15

[mightyace]

Here's one that takes up a bit of land area, the modified cloverstack at TN 840 and I-65 in Harpeth, TN:

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Nashville&sll=38.567863,-121.439904&sspn=0.095562,0.144024&ie=UTF8&hq=&hnear=Nashville,+Davidson,+Tennessee&ll=35.822233,-86.834264&spn=0.024776,0.036006&t=h&z=15

I go through that one almost every day (the last time just 6 hours ago).

Since there are now direct ramps between I-65 and Ellington Parkway that don't touch Briley Parkway, these multiple interchanges (Briley & I-65 plus Briley & Ellington plus Dickerson Rd to I-65/Bridey) could be considered one:
http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Nashville&sll=38.567863,-121.439904&sspn=0.095562,0.144024&ie=UTF8&hq=&hnear=Nashville,+Davidson,+Tennessee&t=h&ll=36.239531,-86.745601&spn=0.025545,0.055747&z=15

[TheStranger]

Here's one that takes up a bit of land area, the modified cloverstack at TN 840 and I-65 in Harpeth, TN:

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Nashville&sll=38.567863,-121.439904&sspn=0.095562,0.144024&ie=UTF8&hq=&hnear=Nashville,+Davidson,+Tennessee&ll=35.822233,-86.834264&spn=0.024776,0.036006&t=h&z=15

I go through that one almost every day (the last time just 6 hours ago).

Since there are now direct ramps between I-65 and Ellington Parkway that don't touch Briley Parkway, these multiple interchanges (Briley & I-65 plus Briley & Ellington plus Dickerson Rd to I-65/Bridey) could be considered one:
http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Nashville&sll=38.567863,-121.439904&sspn=0.095562,0.144024&ie=UTF8&hq=&hnear=Nashville,+Davidson,+Tennessee&t=h&ll=36.239531,-86.745601&spn=0.025545,0.055747&z=15

I remember that interchange well because my best friend and I used the SB I-65 to SB US 31E ramps back in 2006 on our way to a Steely Dan concert...

Another Nashville-area junction that seems to be a combination of multiple interchanges would be the east end of I-440 at I-24, which seems to actually have ramps going back directly to I-40 east:

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Nashville&sll=38.567863,-121.439904&sspn=0.095562,0.144024&ie=UTF8&hq=&hnear=Nashville,+Davidson,+Tennessee&t=k&ll=36.132329,-86.725516&spn=0.018509,0.027595&z=15

[mightyace]

Another Nashville-area junction that seems to be a combination of multiple interchanges would be the east end of I-440 at I-24, which seems to actually have ramps going back directly to I-40 east:

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Nashville&sll=38.567863,-121.439904&sspn=0.095562,0.144024&ie=UTF8&hq=&hnear=Nashville,+Davidson,+Tennessee&t=k&ll=36.132329,-86.725516&spn=0.018509,0.027595&z=15

Not quite.  Going on I-440 East, you have a ramp that heads to I-24 East.  Then, the ramp that goes over I-24 split to join the Murfreesboro Road exit ramp (US 41, 70S) and joins the I-24 West mainline.  It is possible, and I have done it a few times, to go from I-440 East to I-24, 40 West.  Though I'd only do it during "slow" times as you have to cross a few lanes of traffic.

Now, going to I-440 W from I-40 West, there is a dedicated lane that does this plus a lane to I-24 East.

As this interchange is only a mile or two from my bother's apartment, I have driven it quite often.

[TheStranger]

Now that I look at it...so it seems that it's only a partially combined interchange (I-40 west does have the dedicated ramp to I-440 west, but I-440 east only directly links up to the US 70S/US 41 junction before the non-dedicate lanes of 24 west).  Would it still count as one complex, like the Briley/Ellington/65 mix?

[mightyace]

^^^

FWIW I'd say so.  I generally look at that as one mess. 

Sometimes, if I'm headed on I-40 West, I'll go down Briley Parkway itself instead to get to my brother's place, as this way you need to get off at the Briley Parkway exit on I-24 East and that ramp from I-40 W is a left join and you have to slide across 4 lanes of traffic to get from that ramp to the Briley exit.

[Riverside Frwy]

An 8 level stack would be absolutely insane, not to mention expensive.  The flyovers would be incredible, and the exit to the interchange would have to be WAY back in order to have enough room for the flyover to climb to the appropriate height to make it over the stack, especially for the higher levels.  In fact, your ears would probably pop at the very top.

These observations about the altitude of ramps at the top level do not apply if several levels are underground, in tunnel--this has been done with at least one of the I-105 stacks and also the M-40/AP-1 stack near Madrid.

BTW, is there a particular reason why you are not inserting spaces after each period?  I don't mean to sound critical, but the lack of spaces does not make it easy to see where one sentence ends and the next begins.

Well sorry I'm not up to your "standards". I pretty sure you wanted to sound all "smarty pants" but thats ok. There. I put a space after the period. Happy?

EDIT: Sorry to sound like an A$$hole, but I'm sick and I take BS from people I deal with everyday at work. I certainly don't need the BS  from being judged by some guy half across the f-ing planet.

[Scott5114]

Cool it.

[J N Winkler]

Riverside Frwy, it was not my intention to badger you about punctuation.  It just seemed to me that it would be more difficult to touch-type sentences without spaces after the periods (and colons) than simply to insert the spaces.  I wondered, therefore, if you had a particular reason for omitting the spaces, and if so, what that was.

[Mike_OH]

The one that gives a lot of people in the Cincinnati area headaches is the I-75/I-71 junction.  In less than 1/2 mile there are six SB I-75 exits, 5 NB I-71/I-75 Exits, Two SB I-71 Exits, and Three EB US 50 Exits.  There are also Three NB I-75 on-ramps, Two SB on-ramps, and three WB US 50 on-ramps.  The biggest cause of traffic tie-ups at this interchange is the fact that I-75 and I-71 Southbound traffic combines into four lanes at the Brent Spence Bridge.  There is a plan in the works to build a new, larger bridge to replace the current one.

[TheStranger]

The one that gives a lot of people in the Cincinnati area headaches is the I-75/I-71 junction.  In less than 1/2 mile there are six SB I-75 exits, 5 NB I-71/I-75 Exits, Two SB I-71 Exits, and Three EB US 50 Exits.  There are also Three NB I-75 on-ramps, Two SB on-ramps, and three WB US 50 on-ramps.

Don't forget I-471 at the east end of that whole mess...