Interstate to Interstate junctions that contains sharp curves

[jeffandnicole]

Junction of I-80 and I-81 near Hazleton, Pennsylvania has an assortment of very sharp ramps.  Who in Sam Hill approved this design?

[Speeds are recommended maximum speeds as signed by PennDOT]

I-81 S to I-80 E (20 MPH);

I-80 E to I-81 S (30 MPH);

I-81 N to I-80 E (30 MPH);

I-80 E to I-81 N (left exit - 40 MPH);

I-80 W to I-81 N (merges with ramp above - 20 MPH);

I-80 W to I-81 S (15 MPH);

I-81 S to I-80 W (40 MPH); and

I-81 S to I-80 E (20 MPH).

Whoever it was, the DRPA hired them to build their Interstate 76/95 connections, which max out at 25 mph.

[GaryV]

I-75 to I-75 at the I-375 interchange in Detroit has a tight right turn ramp sb and a tight flyover ramp nb.

The stack at I-75/I-696 has all ramps yellow-posted at 35 mph - although 45-50 is plenty safe.

[vdeane]

Pretty much any interstate that meets the Thruway ticket system will qualify for this thread due to the trumpet ramps.  The exception is the I-90 through movements at exit 24 (free-flow except for the toll barrier).  The I-87 NB through movement, though not a trumpet, has similar geometry (SB isn't quite as tight).  Of course, the Thruway through movements are free-flow.

Speaking of I-87, the SB through movement at nearby exit 1 also has a tight curve.  There's a location that looks like it should be an option lane but isn't in order to slow trucks down.

[jp the roadgeek]

Thedirect connections between I-84 and I-91 (ie the ones that don't use CT 15) all have 30 or 35 MPH advisory limits.  The only one that is 35 is the flyover from 84 East to 91 North.  The I-684 North to I-84 East ramp in Brewster has a 35 MPH advisory limit, and is one of the most deceptive sharp curves I've ever encountered.  It feels like a nice high speed ramp, then it turns almost 90° on the dime just before the merge. 

[kphoger]

SB I-35 → SB I-35:  30 mph bend

This one actually somehow manages to throw me off every single time.  For some reason, I keep thinking it must be possible to drive faster than 30-35 mph around that bend, but nope!  Bad idea.

[Strider]

Pretty much any interstate that meets the Thruway ticket system will qualify for this thread due to the trumpet ramps.  The exception is the I-90 through movements at exit 24 (free-flow except for the toll barrier).  The I-87 NB through movement, though not a trumpet, has similar geometry (SB isn't quite as tight).  Of course, the Thruway through movements are free-flow.

Speaking of I-87, the SB through movement at nearby exit 1 also has a tight curve.  There's a location that looks like it should be an option lane but isn't in order to slow trucks down.

Are you talking about the one in Albany, NY? If so, I am still trying to understand why there isn't a direct connection just past the interchange,  especially at the stub end at U.S. 20? Could have fixed that mess between I-90/I-87 as I-87 could have easily stay on the same road, as well as I-90 instead of having both Interstates exit themselves. I know there are Thruway system, but I have seen systems interchange built at Thruway.

[vdeane]

Yep.  As for why, I-87 was planned to follow a road parallel to the Thruway down to exit 23 that never got built (this is also why I-787 ends the way it does).  There were plans in the past couple decades to build a pair of E-ZPass-only ramps there, but it never happened for some reason.

[Strider]

Yep.  As for why, I-87 was planned to follow a road parallel to the Thruway down to exit 23 that never got built (this is also why I-787 ends the way it does).  There were plans in the past couple decades to build a pair of E-ZPass-only ramps there, but it never happened for some reason.

So, if I-87 runs parallel to the Thruway down to exit 23 and meets I-787 there at the Thruway... would I-87 have joined the Thruway from there?

[STLmapboy]

In downtown STL, the WB 55/64 to NB 44 (former 70) ramp is 20 mph.

[kphoger]

In downtown STL, the WB 55/64 to NB 44 (former 70) ramp is 20 mph.

Looking at GSV, it appears the WB-to-NB ramp is 30 mph, but the WB-to-SB ramp is 20 mph.

[vdeane]

Yep.  As for why, I-87 was planned to follow a road parallel to the Thruway down to exit 23 that never got built (this is also why I-787 ends the way it does).  There were plans in the past couple decades to build a pair of E-ZPass-only ramps there, but it never happened for some reason.

So, if I-87 runs parallel to the Thruway down to exit 23 and meets I-787 there at the Thruway... would I-87 have joined the Thruway from there?

Presumably, but from from what I've seen of the originally planned interchange, I'm not sure how the connection would have been made, unless there were to be flyover ramps further up or something.

[Strider]

In downtown STL, the WB 55/64 to NB 44 (former 70) ramp is 20 mph.

Looking at GSV, it appears the WB-to-NB ramp is 30 mph, but the WB-to-SB ramp is 20 mph.

Wow, that bridge seriously needs to be upgraded.

[CoreySamson]

I-10 EB to I-110 NB in Baton Rouge, LA

I-10 WB through the 110 interchange has a 35 mph truck speed limit and a 35 mph warning speed:

https://www.google.com/maps/@30.4370639,-91.1778417,3a,75y,356.31h,89.48t/data=!3m6!1e1!3m4!1svf4CFfu99rCQtQqDFlzZDA!2e0!7i13312!8i6656

[mvak36]

I-290E to I-495N

[jmacswimmer]

I-695 EB to I-83 SB:
https://www.google.com/maps/@39.4086521,-76.666542,3a,64y,45.68h,87.89t/data=!3m6!1e1!3m4!1sE-uNIOwES-gwW70WDTPEMA!2e0!7i16384!8i8192!5m1!1e1?hl=en

And then, a mile and a half later, I-83 NB exiting I-695 EB to continue north:
https://www.google.com/maps/@39.420748,-76.6459255,3a,37.5y,103.23h,90.86t/data=!3m6!1e1!3m4!1smi7MOExkR1nypWiu3eV4Qg!2e0!7i16384!8i8192!5m1!1e1?hl=en

[Rick1962]

I-44 EB exit off WB I-244 in west Tulsa has a 20 MPH advisory speed.

SM-T580

[fillup420]

I-95 south to I-26 east


https://goo.gl/maps/kDWnaNcZNi9TrKzq7

the ramps are in pretty bad shape too

[crispy93]

I feel like any NYC roads are low-hanging fruit, but here goes.

* I-678 north coming off the Whitestone to 95/278 has a sharp 20 or 25 mph curve
* 95 and 87, some very sharp, but cool, 20-25 mph curves
* Anything that 278 touches (278 at the Battery Tunnel (I-478), 278 at 495 (30 mph), 278 at 87 (25 mph, the guardrail is painted black and yellow), 278 at 895 (now NY 895) very sharp 20 mph curve to stay on 278
* 684 ramps onto 84 west or east. 684 backs up for miles approaching 84 because the ramps are so tight, plus the two-lane section between 684 and Danbury, CT really needs another lane
* 84/86 interchange at a cloverleaf

[sparker]

There is still a 25mph loop ramp from NB I-215 to WB I-10 at Colton, CA (all the rest were upgraded to flyovers decades ago).  All the loops at the I-580/680 interchange in Dublin save SB 680>EB 580 are still posted at 25 mph.  Likewise for the terminal ramp from SB I-880 to SB (compass east) I-280 in San Jose.  But one of the more egregious instances -- the TOTSO on EB original I-80, a 35mph "hook" ramp within the turbine-style Oak Park (US 50/CA 99) interchange in Sacramento, was obviated when I-80 was rerouted around the city on the old original I-880 in 1982. 

But even new interchange modifications have some notable curvature -- particularly NB I-215 in Riverside, where the direct ramp continuing that route takes a sharp turn before merging with traffic from CA 91 -- and drops to a single lane, which exits at the next interchange!

[STLmapboy]

I-95 south to I-26 east


https://goo.gl/maps/kDWnaNcZNi9TrKzq7

the ramps are in pretty bad shape too

I feel like a lot of 95 in SC is in bad shape.