DDI with "frontage through" movement

[johndoe]

Florida example: https://www.google.com/maps/d/view?mid=1MMZKi0RdQqjZjtBxmSTznUVnurY&ll=30.159549650095716%2C-81.83194846963146&z=19

I feel like Texas considered this somewhere, but I don't recall seeing one built. 

streetview: https://goo.gl/maps/6bucDJyFTB43zn5R6

[kphoger]

 

[1995hoo]

It makes reasonable sense in that example, given that it eliminates the need for any light at all on the Challenger Drive (east) side of that location. It's also relatively unlikely that Oakleaf Plantation Parkway will be extended east, at least not any time soon, especially if the old munitions in that area haven't been cleaned up yet. I'd kind of like to see that concept used more often in that sort of situation, recognizing in many cases it will be uncommon unless there's a geographic feature like water preventing an extension.

[tradephoric]

Not exactly the same as it's not a frontage road, but here's a half DDI in Maryland.  This interchange use to be roundabouts but they were removed to make room for the DDI:

https://www.google.com/maps/d/u/0/view?mid=1MMZKi0RdQqjZjtBxmSTznUVnurY&ll=39.156095437673976%2C-76.74502006493397&z=18

[Ned Weasel]

It makes sense for a half-DDI, but not for a full DDI.  If it were a full DDI with through frontage road movements, it would be a pair of three-phase signals, which would defeat the purpose of a DDI and make a normal pair of intersections with the frontage roads the better solution.

[jakeroot]

I guess you have to ask yourself which is superior: two, two-phase signals, or a single three-phase signal?

My gut says how they've done it works pretty well, but I also think the standard design for a terminating T/diamond interchange would have been fine too. Credit for creativity, although I think Maryland takes the cake for first terminating-T DDI interchange. At least as we recognize the DDI today.