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

[Henry]

Wow! So this was actually proposed 30 years ago? Seems like the perfect time to do it is now, since the Champaign cloverleaf is getting worked on as of this post.

[PColumbus73]

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.

Judging by the article from @iowahighways , related more to business interests I presume. In reality, does I-80 traffic ricochet, or do they just continue onto I-74/280?

[Rick Powell]

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

As far as traffic, you are correct...about 15% more vehicles go thru the I-39/88 cloverleaf than the Big X.

[Mav94]

The irony in all of this is how GPS is already routing eastbound I-80 traffic not headed for Chicago onto I-280.

[JREwing78]

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

As far as traffic, you are correct...about 15% more vehicles go thru the I-39/88 cloverleaf than the Big X.

I-39 @ I-80 also has greater overall traffic than the "Big X".

But the Big X boasts the highest levels of turning traffic; 4100 vpd in the S to E movement, and 4700 vpd in the W to N movement. The N to W movement (1700 vpd) and E to S movement (2050 vpd) doesn't really seem to warrant separation, except that it's becoming the movement for through traffic to stay on I-74. Otherwise, a modestly wider NBD bridge deck to separate the turning movements would probably suffice.

I-39 @ I-88 will warrant it's own flyovers; the S to E and E to N movements are at 3300 vpd and 3000 vpd, respectively. The W to S and N to W movements carry minimal traffic by comparison. If and when it's warranted, ISHTA could barrier-separate the turning traffic from the WBD mainline to address conflicts.

[Rick Powell]

But the Big X boasts the highest levels of turning traffic; 4100 vpd in the S to E movement, and 4700 vpd in the W to N movement. The N to W movement (1700 vpd) and E to S movement (2050 vpd) doesn't really seem to warrant separation, except that it's becoming the movement for through traffic to stay on I-74. Otherwise, a modestly wider NBD bridge deck to separate the turning movements would probably suffice.

I-39 @ I-88 will warrant it's own flyovers; the S to E and E to N movements are at 3300 vpd and 3000 vpd, respectively. The W to S and N to W movements carry minimal traffic by comparison. If and when it's warranted, ISHTA could barrier-separate the turning traffic from the WBD mainline to address conflicts.

The Feds would rather the change in direction on a marked Interstate route be handled by a curve in the mainline rather than a ramp, especially a tight loop ramp. That's the main reason for the previous concept in iowahighways' post where the design essentially accomplishes that for the change of direction for both I-74 and I-80.

[Brandon]

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

As far as traffic, you are correct...about 15% more vehicles go thru the I-39/88 cloverleaf than the Big X.

I-39 @ I-80 also has greater overall traffic than the "Big X".

But the Big X boasts the highest levels of turning traffic; 4100 vpd in the S to E movement, and 4700 vpd in the W to N movement. The N to W movement (1700 vpd) and E to S movement (2050 vpd) doesn't really seem to warrant separation, except that it's becoming the movement for through traffic to stay on I-74. Otherwise, a modestly wider NBD bridge deck to separate the turning movements would probably suffice.

I-39 @ I-88 will warrant it's own flyovers; the S to E and E to N movements are at 3300 vpd and 3000 vpd, respectively. The W to S and N to W movements carry minimal traffic by comparison. If and when it's warranted, ISHTA could barrier-separate the turning traffic from the WBD mainline to address conflicts.

A bit of a rant here...

But that would require IDOT to actually do something to fix traffic, and without being pushed by some outside force, they don't seem to do much.  It took a state representative to force IDOT to finally widen I-55 from Weber Road south to I-80.  IDOT, in its infinite wisdom, still considers I-55 south of Weber to be a "rural section".  Certain municipalities there used to schedule meetings (at the municipality) at 4 pm deliberately to drive home the point to IDOT officials that something needed to be done.  It also took at least two tries before IDOT finally figured out it would be smarter to rebuild I-80 through Joliet as six consistent lanes instead of the asinine widening and shrinking they had previously proposed.

Working on I-39 and I-88 would also require IDOT to actually work with another agency in the state, which is something they seem reluctant to do.  Note how long the I-90/I-290/IL-53 interchange, with its much higher traffic counts, and turning traffic counts, has languished due to IDOT's lack of cooperation.  As it was, ISHTA had to finally go it alone with minimal assistance from IDOT to rebuild the I-294/I-290/I-88 interchange.  IDOT would rather spend on some stupid Kennedy Expressway repaving job (let's call it was it was - it made no major reconfigurations or changes) that fix ay traffic issue outside the Tri-State.

/rant

[Mav94]

IDOT would rather spend on some stupid Kennedy Expressway repaving job (let's call it was it was - it made no major reconfigurations or changes) that fix ay traffic issue outside the Tri-State.

/rant

Hmm. They're starting/stopping the six-laning of I-57 at Marion instead of extending it all the way down to I-24. You could be on to something.

[Big John]

The missing I in their name?

[Rick Powell]

Hmm. They're starting/stopping the six-laning of I-57 at Marion instead of extending it all the way down to I-24. You could be on to something.

I see I-57 I-24 to 0.7 MI S of IL 13 in Marion additional lanes in the FY 2025 program for $45 million. p. 9-4.

https://idot.illinois.gov/content/dam/soi/en/web/idot/documents/transportation-system/reports/opp/hip/2025%20Internet%20MYP%20Highways%20Book%20List.pdf

[kphoger]

Hmm. They're starting/stopping the six-laning of I-57 at Marion instead of extending it all the way down to I-24. You could be on to something.

Having lived in Herrin...  Hmm...  I didn't remember I-57 being as busy south of Marion as it is north of Marion.  But now I'm looking at the AADT map, and I see that it is.  Yeah, that is weird.

[Mav94]

Hmm. They're starting/stopping the six-laning of I-57 at Marion instead of extending it all the way down to I-24. You could be on to something.

I see I-57 I-24 to 0.7 MI S of IL 13 in Marion additional lanes in the FY 2025 program for $45 million. p. 9-4.

https://idot.illinois.gov/content/dam/soi/en/web/idot/documents/transportation-system/reports/opp/hip/2025%20Internet%20MYP%20Highways%20Book%20List.pdf

Well, that's good. The weave on northbound I-57 between I-24 and the IL 148 exit can be really hairy. It's not like anybody is trying to get to the airport or Lake of Egypt ...

[webny99]

I see I-57 I-24 to 0.7 MI S of IL 13 in Marion additional lanes in the FY 2025 program for $45 million. p. 9-4.

https://idot.illinois.gov/content/dam/soi/en/web/idot/documents/transportation-system/reports/opp/hip/2025%20Internet%20MYP%20Highways%20Book%20List.pdf

Yeah, I was going to say: the rest of the stretch north to Mount Vernon is already being widened, so I'd be pretty surprised if the widening isn't planned to eventually extend south to I-24 as well.

Having lived in Herrin...  Hmm...  I didn't remember I-57 being as busy south of Marion as it is north of Marion.  But now I'm looking at the AADT map, and I see that it is.  Yeah, that is weird.

On the other hand, Marion isn't exactly a large destination city. It makes sense that I-24 would be the start/endpoint of where a widening is warranted.

[Mav94]

On the other hand, Marion isn't exactly a large destination city. It makes sense that I-24 would be the start/endpoint of where a widening is warranted.

There is a truly surprising amount of traffic between St. Louis and Nashville via I-64, I-57, and I-24. So much so that there's advance signage for I-64 on northbound I-57 just north of the I-24 terminus, and at the IL 127 exit on eastbound I-64, the sign specifies "Nashville IL."

[webny99]

On the other hand, Marion isn't exactly a large destination city. It makes sense that I-24 would be the start/endpoint of where a widening is warranted.

There is a truly surprising amount of traffic between St. Louis and Nashville via I-64, I-57, and I-24. So much so that there's advance signage for I-64 on northbound I-57 just north of the I-24 terminus, and at the IL 127 exit on eastbound I-64, the sign specifies "Nashville IL."

Yeah, and the utility of this corridor extends well beyond St. Louis and Nashville in both directions. Kansas City-Atlanta would use this same route.

And... I just ran Google Maps directions for Miami to Denver just for fun. And what do you know?

Recommended route:
I-95 > Fla's Tpke > I-75 > I-24 > I-57 > I-64 > I-70.

Wow.

[Revive 755]

And... I just ran Google Maps directions for Miami to Denver just for fun. And what do you know?

Recommended route:
I-95 > Fla's Tpke > I-75 > I-24 > I-57 > I-64 > I-70.

Wow.

Maybe if something would get done about that missing link between I-24 at Paducah and the US 60 corridor in Missouri (Per Google 30 hr/2,104 miles versus the 29 hours/2,070 miles via St. Louis, plus with the bonus of not dealing with St. Louis traffic and I-70 across Missouri).

[SEWIGuy]

And... I just ran Google Maps directions for Miami to Denver just for fun. And what do you know?

Recommended route:
I-95 > Fla's Tpke > I-75 > I-24 > I-57 > I-64 > I-70.

Wow.

Maybe if something would get done about that missing link between I-24 at Paducah and the US 60 corridor in Missouri (Per Google 30 hr/2,104 miles versus the 29 hours/2,070 miles via St. Louis, plus with the bonus of not dealing with St. Louis traffic and I-70 across Missouri).

That's only 34 miles difference.

[ilpt4u]

57 between Marion/24 and Mt Vernon/64 is getting the 6-laning it needs. As mentioned the Nashville/SE points to St Louis/NW points use this routing, and of course Chicago/NE to Memphis (or Little Rock  )/SW also use this routing. Since 24 ends at 57 instead of continuing west/northwest towards St Louis or I-255, the two diagonal corridors overlap here, hence the needed extra capacity on this stretch

Even get some Chicagoland or Wisconsin->Nashville and SE traffic using the 57/24 routing since it avoids 80/94/Borman, Indianapolis, and Louisville and the bridge toll

[SEWIGuy]

57 between Marion/24 and Mt Vernon/64 is getting the 6-laning it needs. As mentioned the Nashville/SE points to St Louis/NW points use this routing, and of course Chicago/NE to Memphis (or Little Rock  )/SW also use this routing. Since 24 ends at 57 instead of continuing west/northwest towards St Louis or I-255, the two diagonal corridors overlap here, hence the needed extra capacity on this stretch

Even get some Chicagoland or Wisconsin->Nashville and SE traffic using the 57/24 routing since it avoids 80/94/Borman, Indianapolis, and Louisville and the bridge toll

That is definitely the best route to Nashville from around the Madison area.

If I am in Milwaukee or Chicago, I-65 is usually the fastest. But if I have time, I'm taking US-41 south. It takes longer but is generally a very easy drive.

[Mav94]

And... I just ran Google Maps directions for Miami to Denver just for fun. And what do you know?

Recommended route:
I-95 > Fla's Tpke > I-75 > I-24 > I-57 > I-64 > I-70.

Wow.

Maybe if something would get done about that missing link between I-24 at Paducah and the US 60 corridor in Missouri (Per Google 30 hr/2,104 miles versus the 29 hours/2,070 miles via St. Louis, plus with the bonus of not dealing with St. Louis traffic and I-70 across Missouri).

Plenty of traffic already uses IL 146 as a shortcut between I-24 and I-57, which currently turns into US 60 at Sikeston, MO, or between I-24 and I-55. (It would be shorter just to take US 60 out of Paducah, but the Cairo bridges are not to everyone's taste.)

[kphoger]

Marion isn't exactly a large destination city.

No, but Carbondale is a big destination.

Maybe if something would get done about that missing link between I-24 at Paducah and the US 60 corridor in Missouri

Hey man, US-62 → KY-286 → KY-121 to Wickliffe and then the steel truss bridges across both the Ohio and Mississippi:  that's a really nice drive!  Done it several times.  Although, some of the steep drops down into open drainage can be a bit scary when the roads are icy.  Personally, I'm partial to the slightly longer Tick Ridge Road.

[Mav94]

Marion isn't exactly a large destination city.

No, but Carbondale is a big destination.

Not to mention that there's 80,000-100,000 people in the continuous development along IL 13 between Murphysboro and Marion, and hundreds of vacation cabins in Jackson, Johnson, and Williamson counties.

[Revive 755]

Marion isn't exactly a large destination city.

No, but Carbondale is a big destination.

Maybe if something would get done about that missing link between I-24 at Paducah and the US 60 corridor in Missouri

Hey man, US-62 → KY-286 → KY-121 to Wickliffe and then the steel truss bridges across both the Ohio and Mississippi:  that's a really nice drive!

Except KY 286 is signed for local traffic only.

[Molandfreak]

Marion isn't exactly a large destination city.

No, but Carbondale is a big destination.

Maybe if something would get done about that missing link between I-24 at Paducah and the US 60 corridor in Missouri

Hey man, US-62 → KY-286 → KY-121 to Wickliffe and then the steel truss bridges across both the Ohio and Mississippi:  that's a really nice drive!

Except KY 286 is signed for local traffic only.

Is it enforced or enforceable?

[paulthemapguy]

Well this thread certainly went off the rails, lol. tan(this thread) = 75%

I would love to see some flyover ramps connecting NB74 to WB74 and SB80 to EB80, but I don't see it happening anytime soon. I think that's the main conclusion to draw here.

When passing through the QC going westward, I may divert onto 80 or stay straight on 280. Coming east, I almost always use 280 to avoid the sudden cloverleaf. I think people know how to make these maneuvers with minimal slowdown if they're passing through, and this adaptation has lessened the need for flyover ramps to help people match route numbers.