One thing I've always wondered about The Big X in Illinois

[Mav94]

Specifically, who designed the interchange in the first place? This isn't a snarky question. I want to know if the Iowa and Illinois DOTs worked together on it, or if Illinois designed it, or if it was handed down from the Feds. I know it's a really old interchange from before the stack.
 
(Edited to add: I know this might belong more in Great Lakes, but it at least involves Iowa, and most of Illinois acts like the Quad Cities is Iowa anyway)

[edwaleni]

Please clarify, "The Big X" is also the name of an intersection in Medford, Oregon.

[kphoger]

Please clarify, "The Big X" is also the name of an intersection in Medford, Oregon.

He's talking about the cloverleaf interchange of I-80, I-74, and I-280 on the southeast side of the Quad Cities.

[Mav94]

Please clarify, "The Big X" is also the name of an intersection in Medford, Oregon.

He's talking about the cloverleaf interchange of I-80, I-74, and I-280 on the southeast side of the Quad Cities.

This is correct. Sorry, I should have been more clear.

[Rick Powell]

Specifically, who designed the interchange in the first place? This isn't a snarky question. I want to know if the Iowa and Illinois DOTs worked together on it, or if Illinois designed it, or if it was handed down from the Feds. I know it's a really old interchange from before the stack.
 
(Edited to add: I know this might belong more in Great Lakes, but it at least involves Iowa, and most of Illinois acts like the Quad Cities is Iowa anyway)

I don't have a lot of the back history, but in the time frame of its construction the Feds wouldn't have had as much input as they would in the present day, and I'm not sure Iowa would have had much of any design influence since the interchange is not at or near the state line (although they did have influence with AASHTO in the original Interstate route numbering through the Quad Cities and continued to do so whenever re-numbering came up). It was likely mostly a collaboration of the District and central Bureau of Design, with Federal approval. The Wikipedia article on the Big X goes into some detail of what happened and why on the route numbering.

https://en.m.wikipedia.org/wiki/Big_X_(interchange)

[Revive 755]

I think the better question is why this interchange is a cloverleaf and not something similar to I-80 at I-57, or at least the 3 loop/one direct ramp design used for I-72 at US 36 and US 51;I-55 at I-70 and I-270; I-55 at I-72 at 6th Street; and formerly for I-80 at I-94 and IL 394.

[SEWIGuy]

Specifically, who designed the interchange in the first place? This isn't a snarky question. I want to know if the Iowa and Illinois DOTs worked together on it, or if Illinois designed it, or if it was handed down from the Feds. I know it's a really old interchange from before the stack.
 
(Edited to add: I know this might belong more in Great Lakes, but it at least involves Iowa, and most of Illinois acts like the Quad Cities is Iowa anyway)

I don't have a lot of the back history, but in the time frame of its construction the Feds wouldn't have had as much input as they would in the present day, and I'm not sure Iowa would have had much of any design influence since the interchange is not at or near the state line (although they did have influence with AASHTO in the original Interstate route numbering through the Quad Cities and continued to do so whenever re-numbering came up). It was likely mostly a collaboration of the District and central Bureau of Design, with Federal approval. The Wikipedia article on the Big X goes into some detail of what happened and why on the route numbering.

https://en.m.wikipedia.org/wiki/Big_X_(interchange)

They really should have both gone straight through the interchange with the interstate through the Quad Cities being a 3di. I-74 would have just ended at the interchange northwest of Davenport.

[Mav94]

Specifically, who designed the interchange in the first place? This isn't a snarky question. I want to know if the Iowa and Illinois DOTs worked together on it, or if Illinois designed it, or if it was handed down from the Feds. I know it's a really old interchange from before the stack.
 
(Edited to add: I know this might belong more in Great Lakes, but it at least involves Iowa, and most of Illinois acts like the Quad Cities is Iowa anyway)

I don't have a lot of the back history, but in the time frame of its construction the Feds wouldn't have had as much input as they would in the present day, and I'm not sure Iowa would have had much of any design influence since the interchange is not at or near the state line (although they did have influence with AASHTO in the original Interstate route numbering through the Quad Cities and continued to do so whenever re-numbering came up). It was likely mostly a collaboration of the District and central Bureau of Design, with Federal approval. The Wikipedia article on the Big X goes into some detail of what happened and why on the route numbering.

https://en.m.wikipedia.org/wiki/Big_X_(interchange)

Oh, to have been a fly on the wall during those early discussions about numbering ...

Seems like the root of the problem is both I-80 and I-74 make 90 degree turns at their Illinois junction and Illinois (understandably) wanted to avoid (and probably still wants to avoid) the cost of building flyover ramps at the Big X. I know Google Maps sends eastbound through traffic on I-80 onto I-280, and Iowa advises drivers wanting to take I-74 to Peoria to stay on I-80 until the second junction. I suppose it could put up signs approaching the northwest junction advising Chicago-bound traffic to take I-280 instead, just to make it "official." If renumbering the highways was ever going to happen, it already would have.

[SEWIGuy]

Specifically, who designed the interchange in the first place? This isn't a snarky question. I want to know if the Iowa and Illinois DOTs worked together on it, or if Illinois designed it, or if it was handed down from the Feds. I know it's a really old interchange from before the stack.
 
(Edited to add: I know this might belong more in Great Lakes, but it at least involves Iowa, and most of Illinois acts like the Quad Cities is Iowa anyway)

I don't have a lot of the back history, but in the time frame of its construction the Feds wouldn't have had as much input as they would in the present day, and I'm not sure Iowa would have had much of any design influence since the interchange is not at or near the state line (although they did have influence with AASHTO in the original Interstate route numbering through the Quad Cities and continued to do so whenever re-numbering came up). It was likely mostly a collaboration of the District and central Bureau of Design, with Federal approval. The Wikipedia article on the Big X goes into some detail of what happened and why on the route numbering.

https://en.m.wikipedia.org/wiki/Big_X_(interchange)

Oh, to have been a fly on the wall during those early discussions about numbering ...

Seems like the root of the problem is both I-80 and I-74 make 90 degree turns at their Illinois junction and Illinois (understandably) wanted to avoid (and probably still wants to avoid) the cost of building flyover ramps at the Big X. I know Google Maps sends eastbound through traffic on I-80 onto I-280, and Iowa advises drivers wanting to take I-74 to Peoria to stay on I-80 until the second junction. I suppose it could put up signs approaching the northwest junction advising Chicago-bound traffic to take I-280 instead, just to make it "official." If renumbering the highways was ever going to happen, it already would have.

Chicago bound traffic usually takes I-88.

[Rick Powell]

Chicago bound traffic usually takes I-88.

I am sure a lot of it does since it's more of a direct route, at least to the west and north sides. There is always a subset of shunpikers who avoid tolls even though the entire route from the Quad Cities into the Ike costs less than $5 one-way for 2-axles with I-Pass.

I think the better question is why this interchange is a cloverleaf and not something similar to I-80 at I-57, or at least the 3 loop/one direct ramp design used for I-72 at US 36 and US 51;I-55 at I-70 and I-270; I-55 at I-72 at 6th Street; and formerly for I-80 at I-94 and IL 394.

With few exceptions, cloverleafs were the preferred freeway-to-freeway option in the early 60s when that section of I-80 was built and opened. On a side note, I remember talking to an old timer who was in the land acquisition department a few years earlier who tried to get IDOT to consider a more substantial interchange at I-80 and I-55 in the late 50s and was rebuffed; it has taken over 60 years to add a single flyover ramp to that interchange, which is now under reconstruction. The Big X cloverleaf was improved in the late 90's with more gentle ramp curves.   

[SEWIGuy]

Not the Big X, but when the I-80/88 interchange is redone as part of the replacement of the Mississippi River bridge project, a flyover from EB 80 to EB 88 will be constructed. So I think IDOT is well aware that the cloverleafs are problems, but its just a cost issue to replace or upgrade them.

As for the numbering, that's obviously not going to change now. Clearly Iowa's preference for I-80 staying on its current path dates back to when having mainline interstates was a point of pride and seen as an economic driver. (Ironically Iowa has done very little along I-80 in the Quad Cities until recently though.)  Prior to living here, if I ever stopped along I-80 on my way through, it was just to get gas.

[Rick Powell]

Not the Big X, but when the I-80/88 interchange is redone as part of the replacement of the Mississippi River bridge project, a flyover from EB 80 to EB 88 will be constructed. So I think IDOT is well aware that the cloverleafs are problems, but its just a cost issue to replace or upgrade them.

I'd agree with that. I-57 and I-74 in Champaign is getting a similar treatment. Even when implementing a "half stack" instead of a fully directional interchange, the conflicting movements of loop entrance and loop exit ramps are eliminated.

[SEWIGuy]

Btw, I kinda like the I-80N and I-80S idea. Either run I-74 like it is now or have a 3di run through the cities.

[3467]

I was in the Quad Cities today. I took the 74 280 cloverleaf today.
I thought you might enjoy the ancient history . There was the 1947 original interstate plan and the 1953 original turnpike plan which I finally found. Illinois was giving up on the feds by 1953 and turned to the tollway.
Their roads were somewhat different . They originally combine 80 and 88 . The East West begins at the 67 junction in Milan and follows now Illinois 5'it turns North near the current junction where it could meet a future 80 or Iowa turnpike and a turnpike heading south . They cleverly routed it to be 10 miles shorter than the now existing routes.

[3467]

The last numbering fight began just before 5 became 88. I suggest and did to District 2 if it ever comes up to continue 88  to Iowa and neck let them run it up 380.
280 becomes 80. And keep 74 though town because that beautiful bridge warrants a 2di.
As for the Iowa use 80 to 74 they should have dropped that after the bridge was done because it's a better drive.

[The Ghostbuster]

Maybe the early 1990s plan to renumber Interstate 280 as part of Interstate 80, renumber Interstate 80 to Interstate 74 (the portion between 280's western and eastern terminus), and renumber Interstate 74 to Interstate 174 (from its western terminus at Interstate 74 south to its junction with Interstate 280) should have been implemented. Sure, exit renumbering would have been necessary (except on the new 174), but I think it would have certainly cleared up confusion.

[SEWIGuy]

The last numbering fight began just before 5 became 88. I suggest and did to District 2 if it ever comes up to continue 88  to Iowa and neck let them run it up 380.
280 becomes 80. And keep 74 though town because that beautiful bridge warrants a 2di.
As for the Iowa use 80 to 74 they should have dropped that after the bridge was done because it's a better drive.

They don't care that it's a "better drive." They just don't want through traffic going through town and taking the cloverleaf where I-74 meets I-280.

[3467]

It's Iowa making the suggestion not Illinois . It has nothing to do with the Interchange . They posted it during bridge construction. It's better than taking the miserable 80 bridge that has to be replaced.

[SEWIGuy]

It's Iowa making the suggestion not Illinois . It has nothing to do with the Interchange . They posted it during bridge construction. It's better than taking the miserable 80 bridge that has to be replaced.

Well they have since taken that down. The sign is still in place by the I-74/I-80 interchange recommending trough traffic take I-80 - which is smart.

[iowahighways]

Specifically, who designed the interchange in the first place? This isn't a snarky question. I want to know if the Iowa and Illinois DOTs worked together on it, or if Illinois designed it, or if it was handed down from the Feds. I know it's a really old interchange from before the stack.

One thing to keep in mind that hasn't been mentioned yet: Iowa and Illinois agreed to build the I-80 bridge in Le Claire before the I-280 bridge. At the time, there were no river crossings between Bettendorf/Moline and Clinton, while Davenport and Rock Island were already connected via the Centennial and Arsenal bridges.

Maybe the early 1990s plan to renumber Interstate 280 as part of Interstate 80, renumber Interstate 80 to Interstate 74 (the portion between 280's western and eastern terminus), and renumber Interstate 74 to Interstate 174 (from its western terminus at Interstate 74 south to its junction with Interstate 280) should have been implemented. Sure, exit renumbering would have been necessary (except on the new 174), but I think it would have certainly cleared up confusion.

Incidentally, a year after the FHWA shot down Illinois' proposal, the Quad-City Times published a proposal to overhaul the Big X. This clipping was from their August 27, 1994 issue. Aside from the westbound I-80 ramp being rebuilt in the late 1990s, nothing has changed.

[The Ghostbuster]

Would converting The Big X into a stack interchange have been sufficient? Or do the traffic counts not warrant such an interchange reconfiguration?

[Rick Powell]

Would converting The Big X into a stack interchange have been sufficient? Or do the traffic counts not warrant such an interchange reconfiguration?

Something of this scale usually is spurred by reducing crashes, if there aren't serious operational issues. The traffic counts at the Big X are actually a little lighter than I-39/I-80 to the east which has a similar cloverleaf to the current version of the Big X. Other than the long range add-lanes to I-80, the 39/80 interchange isn't on IDOT's radar as it is functioning OK; I'm not sure if there are any long-range plans with the Big X but other than the undesirable ramp moves for through I-80 traffic, I wouldn't be surprised if it's not a high priority. The I-74/I-57 interchange that is getting two flyovers had a history of overturning semi's and crashes and somewhat higher traffic counts than the Big X or 39/80.

[SEWIGuy]

Would converting The Big X into a stack interchange have been sufficient? Or do the traffic counts not warrant such an interchange reconfiguration?

Something of this scale usually is spurred by reducing crashes, if there aren't serious operational issues. The traffic counts at the Big X are actually a little lighter than I-39/I-80 to the east which has a similar cloverleaf to the current version of the Big X. Other than the long range add-lanes to I-80, the 39/80 interchange isn't on IDOT's radar as it is functioning OK; I'm not sure if there are any long-range plans with the Big X but other than the undesirable ramp moves for through I-80 traffic, I wouldn't be surprised if it's not a high priority. The I-74/I-57 interchange that is getting two flyovers had a history of overturning semi's and crashes and somewhat higher traffic counts than the Big X or 39/80.

I personally think I-39/88 is worse than the Big X as well.

[PColumbus73]

Speaking as an outsider, why did renumbering I-74 & 80 get rejected? Was it because of the I-174?

[74/171FAN]

Speaking as an outsider, why did renumbering I-74 & 80 get rejected? Was it because of the I-174?

No, the Iowa legislature passed a bill at some point banning the renumbering of the interstates within the Quad Cities.