Substandard Interchanges

[Beltway]

It's almost like the theory certain people believe that left exits are prohibited on the interstate highways... it's perceived as substandard, but there's no rule against it.

They are prohibited by sound engineering judgement.

But it is not against interstate standards.

It meets basic interstate standards, so that's all it matters.

What is the use of having sound and safe engineering standards and they violating them for political reasons?

[silverback1065]

i'm pretty sure left exits aren't preferred. 

[hbelkins]

Re: cloverleaf interchanges, I thought the rule was that they were allowed in new construction on Interstates, but C/D roads are required. 55/69/269 and 73/85 both meet this, while 69/Pennyrile/WK did not. KYTC probably decided to add direct ramps to better handle traffic loads instead of retrofitting the existing interchange.

I'd be curious to see new traffic counts, now that the configuration of that exit has been in place for awhile, to know how much through I-69 traffic there is now, vs. how much through traffic on the old parkways. I'm going to go out on a limb here and say that the through movements on the E-W WK are still more than the through movements on N-S 69. I don't know how much through N-S Pennyrile traffic existed, or how much traffic transitioned from the WK to or from the Pennyrile. I guess they would have had to have counters on each of the eight ramps in the old cloverleaf to determine that.

As for C/D lanes, they were built for I-65 when the Natcher was extended out to US 231. I don't think any configuration changes are necessary with the conversion of the Natcher to I-65.

[D-Dey65]

I'm not so pleased with the new version of FL 50 and US 27 in Clermont, FL. Most of the ramps are too tight against US 27, and the intersection with Hooks Street between the north to east off-ramp screws everything up.

[Buck87]

Cleveland's "Dead Man's Curve" where the through lanes of I-90 have rumble strips and large 35 mph caution signs because of the near 90 degree turn between the Innerbelt Freeway and the Cleveland Memorial Shoreway, with the OH 2 only portion of the Shoreway having an interchange with I-90 in an elongated and narrow trumpet.   

[cl94]

A few examples I can think of...

- Almost every system interchange in New York City, but particularly the Bruckner Interchange (95/278/678/Hutch), 87/95, 295/495, and 95/Bronx River Parkway. Each of these is a major choke point, with the Bruckner often being considered one of the worst interchanges in the country.  95/BRP is a Breezewood with traffic between the two forced to use the Cross Bronx Expressway service roads. 87/95 and 95/BRP are the two interchanges that set the capacity of the Cross Bronx Expressway
- I-70/I-71/SR 315 in Columbus, Ohio. Left exits, single-lane ramps, major weaving because of nearby interchanges. This interchange is due for a rebuild and traffic flow will likely improve with reconstruction of the eastern 70/71 interchange.
- I-280/Garden State Parkway in East Orange, NJ. It's basically a double trumpet, but replace the trumpets with semi-directional Ts. Major weaving, overloaded single-lane ramps, and there's a ramp toll thrown in there for traffic to the southbound Parkway.
- Classic NY parkway cloverleafs, particularly Wantagh Parkway at NY 24 and the Taconic State Parkway at NY 82. The Taconic example has stop signs for 3 of the entrance ramps.

Cleveland's "Dead Man's Curve" where the through lanes of I-90 have rumble strips and large 35 mph caution signs because of the near 90 degree turn between the Innerbelt Freeway and the Cleveland Memorial Shoreway, with the OH 2 only portion of the Shoreway having an interchange with I-90 in an elongated and narrow trumpet.

Dead Man's Curve is one of the worst interchanges I have ever driven through. Nothing like 90 having to slow to 35 for that curve (which you can't take much faster) while you can go as fast as you want on the SR 2 lanes.

[silverback1065]

Cleveland's "Dead Man's Curve" where the through lanes of I-90 have rumble strips and large 35 mph caution signs because of the near 90 degree turn between the Innerbelt Freeway and the Cleveland Memorial Shoreway, with the OH 2 only portion of the Shoreway having an interchange with I-90 in an elongated and narrow trumpet.

that looks awful! definitely substandard!

[silverback1065]

A few examples I can think of...

- Almost every system interchange in New York City, but particularly the Bruckner Interchange (95/278/678/Hutch), 87/95, 295/495, and 95/Bronx River Parkway. Each of these is a major choke point, with the Bruckner often being considered one of the worst interchanges in the country.  95/BRP is a Breezewood with traffic between the two forced to use the Cross Bronx Expressway service roads. 87/95 and 95/BRP are the two interchanges that set the capacity of the Cross Bronx Expressway
- I-70/I-71/SR 315 in Columbus, Ohio. Left exits, single-lane ramps, major weaving because of nearby interchanges. This interchange is due for a rebuild and traffic flow will likely improve with reconstruction of the eastern 70/71 interchange.
- I-280/Garden State Parkway in East Orange, NJ. It's basically a double trumpet, but replace the trumpets with semi-directional Ts. Major weaving, overloaded single-lane ramps, and there's a ramp toll thrown in there for traffic to the southbound Parkway.
- Classic NY parkway cloverleafs, particularly Wantagh Parkway at NY 24 and the Taconic State Parkway at NY 82. The Taconic example has stop signs for 3 of the entrance ramps.

Cleveland's "Dead Man's Curve" where the through lanes of I-90 have rumble strips and large 35 mph caution signs because of the near 90 degree turn between the Innerbelt Freeway and the Cleveland Memorial Shoreway, with the OH 2 only portion of the Shoreway having an interchange with I-90 in an elongated and narrow trumpet.

Dead Man's Curve is one of the worst interchanges I have ever driven through. Nothing like 90 having to slow to 35 for that curve (which you can't take much faster) while you can go as fast as you want on the SR 2 lanes.

it seems like there's enough room for them to not fuck up that interchange (bruckner)

[CtrlAltDel]

Cleveland's "Dead Man's Curve" where the through lanes of I-90 have rumble strips and large 35 mph caution signs because of the near 90 degree turn between the Innerbelt Freeway and the Cleveland Memorial Shoreway, with the OH 2 only portion of the Shoreway having an interchange with I-90 in an elongated and narrow trumpet.

It's not so much the angle of the turn, as much as it is the radius of the turn, that's the problem.

[sprjus4]

Hampton Roads...

Most of the system interchanges are substandard for today's traffic demand.

I-64/I-464/US-17/VA-168 (Oak Grove Interchange)
I-264/I-664/I-64 (Bowers Hill Interchange)
I-264/I-464 (Downtown Interchange)
I-264/I-64

[Beltway]

Hampton Roads...  Most of the system interchanges are substandard for today's traffic demand.
I-64/I-464/US-17/VA-168 (Oak Grove Interchange)

Basically the same full cloverleaf with one C-D as it was built with on the Interstate legs (I-64 and I-464)

I-264/I-664/I-64 (Bowers Hill Interchange)

A sprawling high capacity interchange with multiple 2-lane semi-directional ramps.
But needs expansion which is in planning.

I-264/I-464 (Downtown Interchange)

Actually handles about the traffic that it and the tunnel and bridge were designed for.  The interchange is constrained by the urban and industrial location.

I-264/I-64

A sprawling high capacity interchange with multiple 2-lane semi-directional ramps.
In its third expansion, the SE quadrant, the others being the NE quadrant and the direct HOV ramps.

[Buck87]

Cleveland's "Dead Man's Curve" where the through lanes of I-90 have rumble strips and large 35 mph caution signs because of the near 90 degree turn between the Innerbelt Freeway and the Cleveland Memorial Shoreway, with the OH 2 only portion of the Shoreway having an interchange with I-90 in an elongated and narrow trumpet.

It's not so much the angle of the turn, as much as it is the radius of the turn, that's the problem.

Good point. The panned fix involves both a larger radius and a less sharp angle. That's currently estimated to happen in the 2025-2029 timeframe, but could get pushed back.

http://www.dot.state.oh.us/projects/ClevelandUrbanCoreProjects/Innerbelt/Pages/default.aspx

[tolbs17]

Is the I-77/I-85 interchange a windmill?

[sprjus4]

Basically the same full cloverleaf with one C-D as it was built with on the Interstate legs (I-64 and I-464)

And is beyond substandard for today's traffic, especially since the completion of the VA-168 Oak Grove Connector in 1999. The explosive and continuing growth south of the Intracoastal Waterway in Chesapeake and Moyock, NC following the completion of the VA-168 Chesapeake Expressway has certainly not helped this, and now with the completion of the US-17 Relocation Project in 2005 and the US-17 Dominion Blvd Expansion in 2017, the Grassfield area south of VA-165 Cedar Rd has been growing up and a more rapid expansion with many developments approved in the last few years around Dominion Blvd are coming / under construction, and even as far south as Elizabeth City, NC has been getting decent development / growth and more planned off of the US-17 Bypass / Halstead Blvd Ext interchange now having easy, convenient 4-lane access to Hampton Roads being only about one hour away. There's advantages of living in North Carolina vs. Virginia, such as cheaper cost of living, etc. and the demand has increased over the year as developments continue to get built.

Looking beyond the interchanges, VA-168 has become a bottleneck between I-64 and VA-165 Mt. Pleasant Rd carrying close to 80,000 AADT, and while US-17 remains adequate, traffic will only continue to grow further as development increases and more demand for that corridor increases. Right now, that corridor sits at about 30,000 AADT.

Ultimately, as growth expands north and south of the state line, VA-168 will need (quite frankly, needs it now) expansion to 8 lanes in the aforementioned segment, eventually 6 lanes to Hillcrest Pkwy, and eventually the freeway design extended to the state line, especially if the NC-168 Currituck County Bypass is ever constructed in the future.  As for US-17, if growth keeps up, again both north and south of the state line, looking 20-30 years in the future, Dominion Blvd will eventually need to be expanded to 6 lanes, and the freeway design extended to the state line (regardless of what happens with I-87. With growth, occurring now and more planned near the bypass at Elizabeth City, and more proposed along the stretch thru Camden County, looking into the future, a completed freeway connection between Elizabeth City and I-64 will be warranted. This was recognized decades ago, well before the I-87 concept, at least on the N.C. side).

IMO, it is the worse one out of all the other interchanges I've mentioned, and VDOT seems to not be paying attention to it. It takes a good 10-15 minutes or greater to travel under a mile from between the Battlefield & Greenbrier interchanges to VA-168 / US-17 South at peak hours on any day. At least two major flyovers are needed on the movements between I-64 East (towards Bowers Hill) to VA-168 / US-17 South, and VA-168 / US-17 North to I-64 East (towards Bowers Hill), along with braided ramps between the I-464 and Battlefield Blvd interchanges.

A sprawling high capacity interchange with multiple 2-lane semi-directional ramps.
But needs expansion which is in planning.

Weaving is a major issue, and the interchange is reaching capacity and can begin to backup at peak hours. The expansion is needed to keep it operationally sound.

Actually handles about the traffic that it and the tunnel and bridge were designed for.  The interchange is constrained by the urban and industrial location.

It may be constrained, but there's certainly traffic congestion issues daily, and is substandard to meet today's needs. Ideally, 4 lanes of traffic in each direction is needed in the tunnel, 6 lanes of traffic in each direction over the bridge, and eliminating the left exits are all needed, but obviously, as you mentioned, there's constraints to this.

A sprawling high capacity interchange with multiple 2-lane semi-directional ramps.
In its third expansion, the SE quadrant, the others being the NE quadrant and the direct HOV ramps.

If you think this interchange is adequate, clearly you've never driven it at peak hours. Even with the ramp additions and HOV connections, there's still large congestion issues in the other quadrants besides the currently under construction quadrant.

The I-264 Corridor Study estimated it would cost $500 million or more to construct the needed improvements to this interchange alone.

A massive overhaul under the proposed Phase #3 project would hopefully address the remainder of the interchange's deficiencies and bring it to meet today's and the future's demands. An Interchange Modification Report is being prepared that will detail proposed improvements that will be released sometime this year.

[kphoger]

Is the I-77/I-85 interchange a windmill?

Who are you?  Don Quixote?   

Seriously, though...  77/85 is a hybrid, but it definitely has elements of the diverging windmill.  A true windmill interchange wouldn't have any loop ramps.

[tolbs17]

Is the I-77/I-85 interchange a windmill?

Who are you?  Don Quixote?   

Seriously, though...  77/85 is a hybrid, but it definitely has elements of the diverging windmill.  A true windmill interchange wouldn't have any loop ramps.

I said that because the ramps are very tight and I hate going down there. That interchange is a clusterfuck.

[kphoger]

I said that because the ramps are very tight and I hate going down there. That interchange is a clusterfuck clusterfybrid.

Edited for clarity.

[Beltway]

Actually handles about the traffic that it and the tunnel and bridge were designed for.  The interchange is constrained by the urban and industrial location.

It may be constrained, but there's certainly traffic congestion issues daily, and is substandard to meet today's needs. Ideally, 4 lanes of traffic in each direction is needed in the tunnel, 6 lanes of traffic in each direction over the bridge, and eliminating the left exits are all needed, but obviously, as you mentioned, there's constraints to this.

No, it would be impossible.  That would have a massive impact on the urban area.  That facility is fully built out. 

A high-level I-264 bridge over both branches of the river has been discussed, but that creates major problems with it towering over the urban area, it having limited or no accessibility to local ramp connections, and how to tie it into the rest of the I-264 facility.

Part of the answer was the parallel Midtown Tunnel and MLK Extension, and the rest of the answer will be the future Uptown Crossing (what I call the I-564 extension to I-664), and the Craney Island Connector to VA-164.

A sprawling high capacity interchange with multiple 2-lane semi-directional ramps.
In its third expansion, the SE quadrant, the others being the NE quadrant and the direct HOV ramps.

If you think this interchange is adequate, clearly you've never driven it at peak hours. Even with the ramp additions and HOV connections, there's still large congestion issues in the other quadrants besides the currently under construction quadrant.

Where did I say that it was adequate for today's traffic?

I described exactly what is there, and portions of the third phase to Witchduck Road are still under construction.

[sprjus4]

No, it would be impossible.  That would have a massive impact on the urban area.  That facility is fully built out.

Agreed, and hence the reason I said that scenario is merely an "ideal" one, but in reality, there's constraints to building such design.

and the rest of the answer will be the future Uptown Crossing (what I call the I-564 extension to I-664), and the Craney Island Connector to VA-164.

I agree generally, but realistically, are those ever going to get built? How much traffic is bound to truly use them if they are built?

Where did I say that it was adequate for today's traffic?

Based on your description of the interchange, the contextualization you gave makes it seem like it's an adequate interchange.

A sprawling high capacity interchange with multiple 2-lane semi-directional ramps.

and for the record, none of the semi-directional ramps are 2-lanes, they're all inadequate single-lane left exits. The only 2-lane ramps that exist on the corridor are I-264 WB to I-64 WB, I-64 EB to I-264 WB, and the recently completed I-64 WB to I-264 EB ramps, and those are all outside ramps.

portions of the third phase to Witchduck Road are still under construction.

The third phase I was referring to is the current project, not the other 90's projects.

Phase 1 is the I-64 WB to I-264 EB direct ramp, completed in October 2019.
Phase 2 is the Newtown Rd and Witchduck interchange improvements, along with the Cleveland St flyover, scheduled for completion in 2021.
Phase 3 is the proposed overhaul to the remainder of the I-64 / I-264 interchange, currently under study.

[kphoger]

substandard ≠ inadequate

I read "sprawling high capacity interchange" to be a critique of its inclusion in a list of substandard interchanges, not a critique of the assertion that it's inadequate for the current traffic levels.

[Beltway]

substandard ≠ inadequate
I read "sprawling high capacity interchange" to be a critique of its inclusion in a list of substandard interchanges, not a critique of the assertion that it's inadequate for the current traffic levels.

Exactly.  It was a high-capacity interchange in its day, and a lot more than a simple cloverleaf, it may have even been "advanced" for its time, but today's traffic volumes make it inadequate.