Parclo Naming Scheme

[SkyPesos]

Here's what I know about Parclo naming currently:

A: Loop ramp(s) from arterial to freeway
B: Loop ramp(s) from freeway to arterial
2: Ramps in two quadrants
4: Ramps in four quadrants

From those above, I know what the A2, B2, A4 and B4 parclos look like. But how about some more unusual or hybrid ones, like the following? I'll make my guesses below, but would most likely need correction


Folded diamond with direct NB to EB and WB to NB ramps instead of left turns. I'm guessing this one is called an AB4, as it's on 4 quadrants, and have loop ramps from both freeway to arterial and arterial to freeway? In this case, a standard folded diamond is probably an AB2 then.


Looks like an A4, but the WB to NB movement is done with a left turn instead of a direct ramp. So maybe an A3, as the NE quadrant is missing ramps?


B4 with missing ramps in the SW quadrant. B3?


Since AB4 is what I'm guessing is for a folded diamond with direct ramps on the other two quadrants, does a BA4 exist?


Two diamond interchanges with a single loop ramp. Are they even considered parclos at this point?

[CtrlAltDel]

As you noticed, the nomenclature does not always distinguish between every variation. So, with that in mind:

Folded diamond with direct NB to EB and WB to NB ramps instead of left turns. I'm guessing this one is called an AB4, as it's on 4 quadrants, and have loop ramps from both freeway to arterial and arterial to freeway? In this case, a standard folded diamond is probably an AB2 then.

Yes.
Yes.

Looks like an A4, but the WB to NB movement is done with a left turn instead of a direct ramp. So maybe an A3, as the NE quadrant is missing ramps?

Yes.

B4 with missing ramps in the SW quadrant. B3?

Yes.

Since AB4 is what I'm guessing is for a folded diamond with direct ramps on the other two quadrants, does a BA4 exist?

They would both be AB4. If you wanted to make a distinction, though, I suppose you could.

Two diamond interchanges with a single loop ramp. Are they even considered parclos at this point?

It gets iffy. But these would be A3 and A4.

[mrsman]

I would imagine that other than A4 and B4, because of their common nature, the descriptions would not be known by most people. 

Parclo A3.  Response: Huh?

So probably every one of the more rare cases would need a diagram for explanation as well.

[kphoger]

Are these designations even used officially, outside of Ontario?