Free-flowing Parclo B4 interchanges

[tradephoric]

I-4 & Maitland Boulevard in Orlando is being reconstructed as a Parclo B4 with grade separated on-ramps.  This allows for entirely free-flowing movements.  Here's the rendering along with a google map link to the current interchange:

https://www.google.com/maps/@28.63091,-81.38746,768m/data=!3m1!1e3

[tradephoric]

Here's another one from Oklahoma City:
https://www.google.com/maps/@35.4781791,-97.5791784,844m/data=!3m1!1e3

Any other interchanges like this out there?

[jwolfer]

I-4 & Maitland Boulevard in Orland is being reconstructed as a Parclo B4 with grade separated on-ramps.  This allows for entirely free-flowing movements.  Here's the rendering along with a google map link to the current interchange:

https://www.google.com/maps/@28.63091,-81.38746,768m/data=!3m1!1e3

That will be better

[jakeroot]

I seem to recall Florida having quite a few of these free-flowing Parclo B4s, particularly near Disney World.

[tradephoric]

Here's an example near Disney World at I-4 & Osceola Pkwy.  It's not completely free-flowing though since it lacks an off-ramp at the SE quadrant of the interchange.

https://www.google.com/maps/@28.34557,-81.53319,793m/data=!3m1!1e3
https://www.google.com/maps/@28.3457224,-81.535906,3a,75y,269.7h,81.63t/data=!3m6!1e1!3m4!1sW00m426cbflrKGDa0YDzCw!2e0!7i13312!8i6656

[froggie]

What little literature I've been able to find suggests that, technically speaking, this is no longer a Parclo B4, as it's fully grade-separated instead of only partially separated, plus you have the two direct ramps with left exits for a total of 8 ramps vice 6.  It's basically a parclo/directional mix.

[Walleye2013]

The interchange between Interstate 81 and Route 309 in Wilkes Barre, Pennsylvania, is Free-flowing, but missing one movement (NB 309-->SB I-81)

https://www.google.ca/maps/@41.2512102,-75.8199042,654m/data=!3m1!1e3

[froggie]

It used to have that movement, but it was at-grade and unsafe, so they closed it about a dozen years ago.

[jeffandnicole]

Ewwww....left hand exits.

At least it looks nice though.

[TheStranger]

Ewwww....left hand exits.

At least it looks nice though.

I think the theory here is that the road with the left-hand ramps is an arterial where in a conventional Parclo B4, drivers would have had to be on the left anyway for a protected left-turn lane to a traditional onramp.  (As opposed to left-hand ramps coming off of a freeway or expressway where it would not be uncommon but certainly not standard)

[wolfiefrick]

Here's a slightly modified oblique Parclo B4 interchange in Wentzville, MO where I-64 ends at I-70. The US-61 SB to I-64 EB ramp was part of old US 40 before the Interstate system went into effect.

[UCFKnights]

Ewwww....left hand exits.

At least it looks nice though.

I think the theory here is that the road with the left-hand ramps is an arterial where in a conventional Parclo B4, drivers would have had to be on the left anyway for a protected left-turn lane to a traditional onramp.  (As opposed to left-hand ramps coming off of a freeway or expressway where it would not be uncommon but certainly not standard)

The road is officially an expressway a few miles down and this project is removing I believe 4 at grade intersections... leaving only 7 left (including driveways), none of which are really major intersections. I imagine the long term plan will be to convert the remainder to an expressway so this will really be a few left exits.

[tradephoric]

Consider the Oklahoma City interchange:
https://www.google.com/maps/@35.4781791,-97.5791784,844m/data=!3m1!1e3

It's obvious that 10th Street is an arterial with no plans for it to be upgraded to a freeway.  Having left-hand ramps at a freeway-to-arterial interchange isn't a big deal.  Plenty of popular interchange designs have left-hand ramps (ie. SPUIs, diamonds, Parclo B4s, etc).

[jeffandnicole]

Consider the Oklahoma City interchange:
https://www.google.com/maps/@35.4781791,-97.5791784,844m/data=!3m1!1e3

It’s obvious that 10th Street is an arterial with no plans for it to be upgraded to a freeway.  Having left-hand ramps at a freeway-to-arterial interchange isn’t a big deal.  Plenty of popular interchange designs have left-hand ramps (ie. SPUIs, diamonds, Parclo B4s, etc).

Eh?

SPUIs and Diamonds are right hand ramps.  The cross street requires you to turn left onto the ramp, but the ramp from/to the highway is on the right.

[tradephoric]

Consider the Oklahoma City interchange:
https://www.google.com/maps/@35.4781791,-97.5791784,844m/data=!3m1!1e3

It's obvious that 10th Street is an arterial with no plans for it to be upgraded to a freeway.  Having left-hand ramps at a freeway-to-arterial interchange isn't a big deal.  Plenty of popular interchange designs have left-hand ramps (ie. SPUIs, diamonds, Parclo B4s, etc).

Eh?

SPUIs and Diamonds are right hand ramps.  The cross street requires you to turn left onto the ramp, but the ramp from/to the highway is on the right.

What's the problem?  Take a closer look at the I-44/10th Street interchange.  The ramps from/to the highway are on the right (just like you like).  There isn't an issue here.

[jakeroot]

Consider the Oklahoma City interchange:
https://www.google.com/maps/@35.4781791,-97.5791784,844m/data=!3m1!1e3

It's obvious that 10th Street is an arterial with no plans for it to be upgraded to a freeway.  Having left-hand ramps at a freeway-to-arterial interchange isn't a big deal.  Plenty of popular interchange designs have left-hand ramps (ie. SPUIs, diamonds, Parclo B4s, etc).

Eh?

SPUIs and Diamonds are right hand ramps.  The cross street requires you to turn left onto the ramp, but the ramp from/to the highway is on the right.

What's the problem?  Take a closer look at the I-44/10th Street interchange.  The ramps from/to the highway are on the right (just like you like).  There isn't an issue here.

I think the issue is your use of "left-hand ramps" in your original comment (above, bold). More precisely, the majority of service junctions have left and right turns, but most junctions don't, by design, use left-hand ramps. I despise left-hand ramps, but in the case of these free-flowing B4s (or cloverstacks), I don't see the issue because, if anything, it spreads out the traffic evenly along the arterial, where "keep right" laws are likely not enforced. The only issue might be if the arterial has future plans to become a freeway. The left-hand ramps may become an issue at that point.

[tradephoric]

Here's another B4 cloverstack from Oklahoma City. 

https://www.google.com/maps/@35.5114134,-97.5759067,503m/data=!3m1!1e3

[tradephoric]

And here's an A4 cloverstack outside Atlanta at I-285 & Harvey Mathis Pkwy. 

https://www.google.com/maps/@33.9115636,-84.3569969,628m/data=!3m1!1e3

[jakeroot]

And here's an A4 cloverstack outside Atlanta at I-285 & Harvey Mathis Pkwy. 

https://www.google.com/maps/@33.9115636,-84.3569969,628m/data=!3m1!1e3

I don't think this one is as interesting, given that it's between two freeways (the OKC example is better, because one leg of the junction is arterial roadway). Freeway-to-freeway junctions should always have right-side ramps, unless there's HOV ramps involved.

[tradephoric]

Look at this interchange at I-495 & Union Street in Massachusetts.  I'd call it a Parclo B4 cloverstack / superstreet interchange.  Whatever you call it, there are no traffic signals to speak of which keeps traffic flowing on the arterial.

https://www.google.com/maps/@42.6786084,-71.1524953,645m/data=!3m1!1e3

[jeffandnicole]

Look at this interchange at I-495 & Union Street in Massachusetts.  I'd call it a Parclo B4 cloverstack / superstreet interchange.  Whatever you call it, there are no traffic signals to speak of which keeps traffic flowing on the arterial.

https://www.google.com/maps/@42.6786084,-71.1524953,645m/data=!3m1!1e3

495 South to 28 North traffic has to use 28 South first though.  And only a 35 mph speed limit thru there.

[tradephoric]

495 South to 28 North traffic has to use 28 South first though.  And only a 35 mph speed limit thru there.

Yep, that's the superstreet movement that you are describing.  In a previous thread you were questioning if a superstreet interchange exists in the real world.  Well the movement you just described is an example of a superstreet interchange.