Interstate to Interstate Slow-speed Exits

Started by Jordanes, June 03, 2017, 10:10:06 PM

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hbelkins

I-76 to I-70 is so slow it has a stoplight.  :bigass:


Government would be tolerable if not for politicians and bureaucrats.


tckma


DeaconG

I-295 NB to I-10 WB, 25 MPH tight curve, god help you if a truck's in front of you. This needed a flyover yesterday.
Dawnstar: "You're an ape! And you can talk!"
King Solovar: "And you're a human with wings! Reality holds surprises for everyone!"
-Crisis On Infinite Earths #2

Darkchylde

Non-cloverleaf example: Most of the interstate-to-interstate interchanges in the KC Downtown Loop. Very tight quarters and low speeds on the main highways to begin with (mostly at 40) means you might have a really tight flyover ramp signed for 30 or so MPH.

rte66man

In OKC (not a loop ramp):

- I44 NB to I240 EB
- I40 both EB and WB at the Fort Smith junction.  Even after the rebuild to eliminate the weaving, the main I40 lanes cannot be taken safely over about 50 MPH.
- I44 WB at the Turner Turnpike western end.
When you come to a fork in the road... TAKE IT.

                                                               -Yogi Berra

bing101

#55
 I-93 the parkway section in New Hampshire has to have the narrowest ramps for an interstate.


https://www.youtube.com/watch?v=Vu2_XIr4M_M

michravera

Quote from: Jordanes on June 03, 2017, 10:10:06 PM
What interstate to interstate connections are not full expressway-grade? I don't mean things like Breezewood, I mean more like just slow-speed connections, or with weird exits as part of it? The one which comes to mind to me is I-64 east to I-564 east, or the reverse of I-564 west to I-64 west. It's rather slow-speed, and there is an exit to Granby Street sandwiched in there, too. What other examples exist?

I believe that the NB I-580 to WB I-80 connector in Reno is advised down to 20 MPH. They may have fixed that as part of the upgrade, but last I was there, the upgrade was apparently done and the advisory was unchanged. IIRC, the WB I-80 to SB I-680 in Cordelia, CA is advised down to 25 or so. I am not sure that all of the I-580/I-880 connectors in Alameda County, CA have high speed ramps. If not, it would be usual to advise them down to no higher than 40 MPH. Ditto for I-280/I-380 in San Mateo County.
Unsigned WB I-305 also has a slow connection onto SB I-5 in Sacramento.

TheOneKEA

The northern end of the overlap between I-83 and I-695 near Towson, MD was originally a tight trumpet interchange, later rebuilt into a semi-directional T. The rebuild resulted in I-83 north following a very tight ramp with a sharp curve that bends to pass beneath I-695 and then bends again to merge with the ramp from I-695 west. The walls along the outer edge of the Raman show lots of scars and scuffs from vehicles taking that ramp too quickly.

tckma

Quote from: bing101 on July 10, 2017, 12:50:03 AM
I-93 the parkway section in New Hampshire has to have the narrowest ramps for an interstate.

For many years, up to I think about 2006, this portion was signed "TO I-93" and had a separate set of exit numbers (1, 2, 3) that were out of sequence from the rest of NH I-93, because the Franconia Notch Parkway was not built to Interstate standards -- the surrounding environment would have been damaged too much.

It was grandfathered in, they re-signed it as I-93, and renumbered the exits so that they are in sequence.

I don't remember if the exit numbers were changed before or after I moved out of New England, but to me, it seems like a recent change.  (Then again, so does PA's conversion to milepost-based exit numbers, which happened almost 15 years ago now.  At least it still seems weird to me to see milepost-based exit numbers on I-80, I-380, and the northern part of I-81, since I used to take those to get to college... Down near where I live now, the milepost-based numbers seem normal.)

SFalcon71

I-70 and I-81 in Hagerstown, MD always takes ages to get through. Between construction, traffic, and the design is awful as well.

michravera

Quote from: cpzilliacus on June 10, 2017, 12:10:18 AM
Quote from: roadguy2 on June 09, 2017, 11:13:13 PM
Quote from: cpzilliacus on June 09, 2017, 08:19:24 PM
Any freeway-freeway interchange in Los Angeles County or Orange County in California that features a ramp meter on the ramp (yes, these are pretty common in the Southland). Here's an example on a ramp leaving the impressive stack interchange at the junction of I-405 and I-105 (traffic from I-405 southbound to I-105 eastbound) near LAX.

Here's a view of the stack from the northbound lanes of I-405.

I have never heard of ramp meters on freeway-freeway interchanges. Is there any other place besides south CA that has them on these?

I have not seen them elsewhere with my own eyes, but I have been told that they do exist in other places.

Certainly some of the CASR-85 to CASR-17 movements.

hbelkins

Just did this one today. I-275 north to I-74/US 52 west in Ohio. Signed for 25 mph and agonizingly slow when a truck in front of you follows the advisory speed.


Government would be tolerable if not for politicians and bureaucrats.

sparker

Since many of the cited examples are cloverleaf types, I've got a question that someone out there might be able to answer:  Are more recent examples of cloverleaves constructed to higher-speed standards; as an example I'd point to the I-55/69/(nascent 269) interchange at Hernando, MS, as well as the under-construction I-22/I-269 interchange several miles to the east.  Do the advisory speeds for the loops exceed 25 mph for either facility?  One would think that even for a cloverleaf type, any newer and more rural examples of freeway-to-freeway types would occupy enough land to expand the radius of these loops to accommodate 30-35 mph at the least.  Any thoughts? 

tckma

Quote from: SFalcon71 on August 04, 2017, 11:49:04 PM
I-70 and I-81 in Hagerstown, MD always takes ages to get through. Between construction, traffic, and the design is awful as well.

Meh, it's a standard cloverleaf, and besides, no one in Annapolis gives a crap about anything west of Frederick. ;)

I've never had a problem with it, but I don't get out to western MD much.

SFalcon71

Quote from: tckma on August 07, 2017, 11:53:17 AM
Quote from: SFalcon71 on August 04, 2017, 11:49:04 PM
I-70 and I-81 in Hagerstown, MD always takes ages to get through. Between construction, traffic, and the design is awful as well.

Meh, it's a standard cloverleaf, and besides, no one in Annapolis gives a crap about anything west of Frederick. ;)

You got that right!

jwolfer

#65
Not interstate to interstate but both high-speed limited access none the less.

i4 junction with Florida turnpike and i4 junction with SR408.. The classic toll road double trumpets.

The 408 junction backs up really badly. But no longer a toll booth

At the turnpike the sunpass lanes say you have to go 25mph.. Very few go that slow

Both are being reconstructed with the i4 ultimimate project with AET.

LGMS428

JKRhodes

Interstate 10 at Interstate 20 in Texas. The W/B I-20 to E/B I-10 movement requires merging across two lanes followed by a 35 MPH U-turn. One can see from the satellite view that the movement was once on a tighter radius.

https://goo.gl/maps/BRwN4gzauXR2

Truvelo

#67
This exit was particularly nasty before they rebuilt it, especially when there's a truck in front.

Speed limits limit life

intelati49

Quote from: sparker on August 06, 2017, 10:24:56 PM
Since many of the cited examples are cloverleaf types, I've got a question that someone out there might be able to answer:  Are more recent examples of cloverleaves constructed to higher-speed standards; as an example I'd point to the I-55/69/(nascent 269) interchange at Hernando, MS, as well as the under-construction I-22/I-269 interchange several miles to the east.  Do the advisory speeds for the loops exceed 25 mph for either facility?  One would think that even for a cloverleaf type, any newer and more rural examples of freeway-to-freeway types would occupy enough land to expand the radius of these loops to accommodate 30-35 mph at the least.  Any thoughts? 

1. Yes. I do believe the newer clover in Joplin is signed as 35MPH. In your example the -55 clover is signed as 30mph
2. I know for a fact that the I-22 interchange includes full (NB/SB/EB/WB) C/D roads, which migrates the issues of the merging into the slow speed exits. I'm not as worried about that one.

jecht

Quote from: Truvelo on August 16, 2017, 04:32:52 AM
This exit was particularly nasty before they rebuilt it, especially when there's a truck in front.



What was the old interchange like? Was it a double trumpet or something else?

Flint1979

I-75 to I-75 in Detroit. In the NE corner of downtown Detroit I-75 switches from the Fisher Freeway to the Chrysler Freeway and vice versa in the other direction. I-375 is a continuation of the Chrysler Freeway but in order to switch from the Fisher to the Chrysler or the other way around you have to go through a 25 mph exit ramp to stay on I-75.

TheStranger

California examples:

There's the ramp from US 101 north to I-10 east at the San Bernardino Split near downtown Los Angeles, which was an Interstate-Interstate junction from 1965-1968 (the unsigned I-105 with unsigned I-110). 

Unsigned I-305 (US 50, former I-80) at I-5 in Sacramento has 30 MPH ramps:
https://www.google.com/maps/@38.569354,-121.5139527,3a,37.9y,133.21h,87.22t/data=!3m6!1e1!3m4!1sPPeleIJVDa4YOcd7qA6t0A!2e0!7i13312!8i6656

This might be the slowest one I've seen so far: 20 MPH ramp from I-10 west to I-710 south near Monterey Park
https://www.google.com/maps/@34.0614933,-118.1654579,3a,75y,287.23h,87.28t/data=!3m7!1e1!3m5!1sWTlrXuviFEVqmcqPA5jT-Q!2e0!6s%2F%2Fgeo2.ggpht.com%2Fcbk%3Fpanoid%3DWTlrXuviFEVqmcqPA5jT-Q%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D55.206158%26pitch%3D0%26thumbfov%3D100!7i13312!8i6656

Another 20 MPH example: I-8 east to I-15 north, San Diego
https://www.google.com/maps/@32.7783864,-117.11298,3a,40y,102.04h,91.56t/data=!3m7!1e1!3m5!1sDN3b3GLCTz_X32Js4G73_A!2e0!6s%2F%2Fgeo3.ggpht.com%2Fcbk%3Fpanoid%3DDN3b3GLCTz_X32Js4G73_A%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D326.33795%26pitch%3D0%26thumbfov%3D100!7i13312!8i6656

I-80 west to I-780 east in Vallejo, 30 MPH cloverleaf ramp
https://www.google.com/maps/@38.0914952,-122.230775,3a,75y,191.86h,90.2t/data=!3m7!1e1!3m5!1si-o7q1IL4bUAWbDqiiJcbw!2e0!6s%2F%2Fgeo1.ggpht.com%2Fcbk%3Fpanoid%3Di-o7q1IL4bUAWbDqiiJcbw%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D106.47363%26pitch%3D0%26thumbfov%3D100!7i13312!8i6656

I-880 south to I-280 south in San Jose, 25 MPH cloverleaf
https://www.google.com/maps/@37.3170082,-121.9406323,3a,75y,189.66h,87.31t/data=!3m7!1e1!3m5!1sV0_pD9sf8GZThruv3IRXpw!2e0!6s%2F%2Fgeo3.ggpht.com%2Fcbk%3Fpanoid%3DV0_pD9sf8GZThruv3IRXpw%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D0.25192702%26pitch%3D0%26thumbfov%3D100!7i13312!8i6656

I-110 north to I-105 west in Los Angeles, 25 MPH cloverleaf
https://www.google.com/maps/@33.929384,-118.2798765,3a,75y,1.88h,89.04t/data=!3m7!1e1!3m5!1sar0nC9raMiiKW4gvJNERsg!2e0!6s%2F%2Fgeo3.ggpht.com%2Fcbk%3Fpanoid%3Dar0nC9raMiiKW4gvJNERsg%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D152.10274%26pitch%3D0%26thumbfov%3D100!7i13312!8i6656

I-405 south to I-110 north:
https://www.google.com/maps/@33.8558932,-118.2842789,3a,39.2y,127.64h,88.3t/data=!3m7!1e1!3m5!1s8gyOH2Lwwa6Mwt3xX1GrnA!2e0!6s%2F%2Fgeo0.ggpht.com%2Fcbk%3Fpanoid%3D8gyOH2Lwwa6Mwt3xX1GrnA%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D114.227715%26pitch%3D0%26thumbfov%3D100!7i13312!8i6656

I-710 south to I-405 south
https://www.google.com/maps/@33.8260196,-118.2076612,3a,75y,175.18h,90t/data=!3m6!1e1!3m4!1suothkLnrilxPYGONaucr2Q!2e0!7i13312!8i6656

I-215 north to I-10 west, Colton
https://www.google.com/maps/@34.0647744,-117.2959124,3a,75y,27.52h,89.37t/data=!3m7!1e1!3m5!1sswKXihtbd6VEqYVjrykZSA!2e0!6s%2F%2Fgeo3.ggpht.com%2Fcbk%3Fpanoid%3DswKXihtbd6VEqYVjrykZSA%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D110.881714%26pitch%3D0%26thumbfov%3D100!7i13312!8i6656

I-8 west to I-5 south, San Diego
https://www.google.com/maps/@32.7580144,-117.2043389,3a,75y,214.53h,88.18t/data=!3m7!1e1!3m5!1soZ5mNBrYJiGAvAIMg1YwOQ!2e0!6s%2F%2Fgeo0.ggpht.com%2Fcbk%3Fpanoid%3DoZ5mNBrYJiGAvAIMg1YwOQ%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D124.212875%26pitch%3D0%26thumbfov%3D100!7i13312!8i6656
Chris Sampang

hbelkins

Quote from: jecht on October 24, 2017, 05:15:06 PM
Quote from: Truvelo on August 16, 2017, 04:32:52 AM
This exit was particularly nasty before they rebuilt it, especially when there's a truck in front.



What was the old interchange like? Was it a double trumpet or something else?

No, it was a trumpet that had issues only because idiot drivers couldn't read the signs and drove too fast on the loop ramp that carried I-79 north. And because idiot drivers couldn't or didn't read and obey the signs, PennDOT wasted millions to rebuild the exit.


Government would be tolerable if not for politicians and bureaucrats.

Bitmapped

Quote from: hbelkins on October 25, 2017, 10:39:29 AM
Quote from: jecht on October 24, 2017, 05:15:06 PM
Quote from: Truvelo on August 16, 2017, 04:32:52 AM
This exit was particularly nasty before they rebuilt it, especially when there's a truck in front.



What was the old interchange like? Was it a double trumpet or something else?

No, it was a trumpet that had issues only because idiot drivers couldn't read the signs and drove too fast on the loop ramp that carried I-79 north. And because idiot drivers couldn't or didn't read and obey the signs, PennDOT wasted millions to rebuild the exit.

As someone who drives through that interchange several times a month, it needed rebuilt. The interchange is at the bottom of a hill. For I-79 NB, you'd come down a mile-long grade, go through a 25mph loop, and then have to merge in to I-70 WB going uphill with a short merge lane. Good luck if you got stuck behind a truck. The new flyover ramp has a 40mph advisory speed but can easily be taken at 55 in a car.

I don't think anything is in the works, but I'd like to see something done about the ramp from I-70 EB to I-79 SB. The ramp comes downhill from I-70 (you can do 35-40 on it in a car) then starts a mile-long climb uphill to US 40. You'll get a line of trucks backed up going uphill. A higher speed ramp that flew over Vance Station Road to minimize the grade would be helpful.

lepidopteran

#74
The (western end of) I-76 to I-71 interchange used to be pretty slow; what was up with a double trumpet when neither is a toll road?  However the freeway-to-freeway movements have since been replaced with more sensible ramps.  Trumpet remnants are still in place for the fourth direction of at-grade US-224.

While not nearly as problematic as its infamous counterpart, I-70 EB at New Stanton is kind of slow.  It's a double trumpet, with a kind of tight loop ramp leading onto the PA Turnpike itself.  How feasible would a direct EB connector ramp be?  It would have to incline and curve upward over a railroad and the Sewickley Creek.  The WB route isn't as bad, as it's pretty much just one elongated loop -- plus the recently-completed improvements at the New Stanton exit off "free" I-70 might help get traffic get up to speed quicker.




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