Florida Town Considers Being the First with a Center Turn Overpass

[kernals12]

Pembroke Pines is considering becoming the first in the world with another innovative intersection, the center turn overpass


This one is extremely simple, it adds a grade separated structure for left turn movements meaning left turn phases at the main intersection can be eliminated.

Two are being considered both on Pines Boulevard, one at Flamingo Road and the other at University Drive. Estimated cost is $35 million, which is less than what a normal interchange would cost, in addition to needing less right of way. Construction would not begin before 2023

[1995hoo]

Pembroke Pines is considering to be the first in the world with another innovative intersection, the center turn overpass
....

This one is extremely simple, it adds a grade separated structure for left turn movements meaning left turn phases at the main intersection can be eliminated.

Where, precisely? My brother-in-law lives in Pembroke Pines and I might ask him about if you know where it's being considered (this because if he doesn't know about it and asks where, I want to have an answer). My guess would be Pines Boulevard at Flamingo Road because there are so many crashes there.

[kernals12]

Pembroke Pines is considering to be the first in the world with another innovative intersection, the center turn overpass
....

This one is extremely simple, it adds a grade separated structure for left turn movements meaning left turn phases at the main intersection can be eliminated.

Where, precisely? My brother-in-law lives in Pembroke Pines and I might ask him about if you know where it's being considered (this because if he doesn't know about it and asks where, I want to have an answer). My guess would be Pines Boulevard at Flamingo Road because there are so many crashes there.

Uncanny
http://sfmn.fiu.edu/pembroke-pines-ponders-overpass-touted-as-one-of-a-kind/

[jeffandnicole]

Why does it appear there's a left turn arrow in the left lane of the graphic?

[kernals12]

Why does it appear there's a left turn arrow in the left lane of the graphic?

Bad rendering. For the same reason there's two Renaults, not sold in the United States, at an intersection in Florida.

[1995hoo]

Why does it appear there's a left turn arrow in the left lane of the graphic?

Because there are left-turn lanes there now and they just stuck the digitized rendering into an existing photo.

[kernals12]

Look at how much material this structure needs. This is why I've been so interested in advances in Concrete.

[US 89]

Look at how much material this structure needs.

That is likely the reason why none of these exist yet. I'm no traffic engineer, but I would bet that any improvements in traffic flow this would get you don't justify the cost of the bridges.

[CtrlAltDel]

Part of the issue is that one intersection is floating right on top of the other. Moving the upper intersection a bit might be helpful (forgive the poor rendering):

[Rick Powell]

Look at how much material this structure needs.

Part of the issue is that one intersection is floating right on top of the other. Moving the upper intersection a bit might be helpful (forgive the poor rendering):

That is likely the reason why none of these exist yet. I'm no traffic engineer, but I would bet that any improvements in traffic flow this would get you don't justify the cost of the bridges.

I remember looking at one for a location in IL - the expected performance wasn't as great as you might have thought compared to other designs. True, one of the legs could be offset, but it would only save the lane widening in that direction, and require more land (and possibly building removals, utility moves, etc.) in the offset direction.

[The Ghostbuster]

Intriguing proposal. I would like to know what the locals think of this proposal. I doubt Pembroke Pines could just build this without seeking input from the surrounding communities.

[1995hoo]

Part of the issue is that one intersection is floating right on top of the other. Moving the upper intersection a bit might be helpful (forgive the poor rendering):

Whether that would be acceptable might depend in part on what they're willing to condemn or pave over in order to offset it. There's a park and a shopping mall on the north side of Pines Boulevard and various businesses on the south side. This is the intersection in question. North is up.

It still won't solve one fundamental problem in that area–excessive speeding. The speed limit on Pines Boulevard is 45. It's not unusual to see people going well over 60 mph. But that's more of an "idiot Miami-area drivers" problem than anything else.

[Plutonic Panda]

I've always wondered about doing this to certain intersections and assumed they existed somewhere. Is this a first in the world or just the USA? Color me very surprised this hasn't been done anywhere. Seems like a no brainer compromise for many situations.

[1995hoo]

I've always wondered about doing this to certain intersections and assumed they existed somewhere. Is this a first in the world or just the USA? Color me very surprised this hasn't been done anywhere. Seems like a no brainer compromise for many situations.

The closest thing I think I've ever seen is at the intersection of Summerlin Road and Gladiolus Drive in Fort Myers, although that intersection uses only two ramps, configured like "tangent turns," for the prevailing left-turn movements (beach-bound traffic going westbound from Gladiolus to Summerlin; eastbound traffic on Gladiolus towards downtown). I suspect the left-turn movement from northbound Summerlin to westbound Gladiolus is a lot less used because people would use Winkler Road nearby to cut the corner. I have no idea about the other direction.

(Those ramps were built sometime after 2005. I first visited Fort Myers that year at Thanksgiving and the ramps didn't exist then. We were staying in a beachfront hotel in Fort Myers Beach and went through this intersection quite a few times.)

[Plutonic Panda]

I like that idea the best because it eliminates lights completely for left turn but is costly and becomes even more costly if you want have it fully directional instead of half. That is a cool intersection. Thanks for sharing that.

[1995hoo]

I like that idea the best because it eliminates lights completely for left turn but is costly and becomes even more costly if you want have it fully directional instead of half. That is a cool intersection. Thanks for sharing that.

It's even cooler at night when you go over the flyovers due to the lighting they mounted on the walls on either side that gives a neat visual effect, but I don't have any pictures to share. If you look at this Street View, though, you can get a sense for what the lighting is.

[D-Dey65]

I remember when this was recommended for US 19 and Ridge Road in Port Richey. I still think a diamond interchange would be better.

[FLRoads]

The closest thing I think I've ever seen is at the intersection of Summerlin Road and Gladiolus Drive in Fort Myers, although that intersection uses only two ramps, configured like "tangent turns," for the prevailing left-turn movements (beach-bound traffic going westbound from Gladiolus to Summerlin; eastbound traffic on Gladiolus towards downtown). I suspect the left-turn movement from northbound Summerlin to westbound Gladiolus is a lot less used because people would use Winkler Road nearby to cut the corner. I have no idea about the other direction.

(Those ramps were built sometime after 2005. I first visited Fort Myers that year at Thanksgiving and the ramps didn't exist then. We were staying in a beachfront hotel in Fort Myers Beach and went through this intersection quite a few times.)

Those ramps were completed by the end of 2006. And you are correct, the northbound to westbound and southbound to eastbound movements from Summerlin Road (CR 869) to Gladiolus Drive (CR 865) are used less, though I just used the southbound to eastbound movement last Friday . FWIW, I was the only one in the queue at the time.

It's even cooler at night when you go over the flyovers due to the lighting they mounted on the walls on either side that gives a neat visual effect, but I don't have any pictures to share. If you look at this Street View, though, you can get a sense for what the lighting is.

I thought that was an interesting concept to embed the lights within the barriers. I know when the ramps first opened the lights were amber, but since I haven't driven through there at night in years, I wonder if Lee County DOT has switched them out for LEDs...

[MCRoads]

The thing is, all these renders are missing 1 thing... the intersection probably wouldn't be floating above the intersection! As the left/hand movements are on the bridge, a central column would probably be placed on an island in the middle of the intersection.

[kernals12]

The thing is, all these renders are missing 1 thing... the intersection probably wouldn't be floating above the intersection! As the left/hand movements are on the bridge, a central column would probably be placed on an island in the middle of the intersection.

Good idea, that would probably reduce the cost and discourage people from going left at the main intersection.

[1995hoo]

On the other hand (since I've driven through that intersection many times), I can't help but wonder how many reckless drivers going way too fast would plow into the central column.

The overall idea is interesting. I still haven't gotten around to asking my brother-in-law if he knows about it. My wife is taking to him on the phone right now, but you'll surely understand why I'm not going to interrupt to ask about an intersection design (I can hear what she's talking about and it would NOT be appropriate to interrupt to ask about roads!).

[architect77]

I like that idea the best because it eliminates lights completely for left turn but is costly and becomes even more costly if you want have it fully directional instead of half. That is a cool intersection. Thanks for sharing that.

So why can't they add Jersey Jughandle to accommodate the left turn? Or a Michigan left (u-turn past intersection) ?

[kernals12]

I like that idea the best because it eliminates lights completely for left turn but is costly and becomes even more costly if you want have it fully directional instead of half. That is a cool intersection. Thanks for sharing that.

So why can't they add Jersey Jughandle to accommodate the left turn? Or a Michigan left (u-turn past intersection) ?

Those require more row

[Avalanchez71]

Pembroke Pines is considering to be the first in the world with another innovative intersection, the center turn overpass
....

This one is extremely simple, it adds a grade separated structure for left turn movements meaning left turn phases at the main intersection can be eliminated.

Where, precisely? My brother-in-law lives in Pembroke Pines and I might ask him about if you know where it's being considered (this because if he doesn't know about it and asks where, I want to have an answer). My guess would be Pines Boulevard at Flamingo Road because there are so many crashes there.

SR 820 and SR 823 were two lanes back in the 80s. Little to no issues.  They expanded the lanes and now there is so much traffic that the lanes do no justice.  Expanding lanes is not a panacea. 

[Sani]

It's even cooler at night when you go over the flyovers due to the lighting they mounted on the walls on either side that gives a neat visual effect, but I don't have any pictures to share. If you look at this Street View, though, you can get a sense for what the lighting is.

I thought that was an interesting concept to embed the lights within the barriers. I know when the ramps first opened the lights were amber, but since I haven't driven through there at night in years, I wonder if Lee County DOT has switched them out for LEDs...

The lights can honestly be a little distracting, because if you're in a car that's fairly close to the ground, you end up with this kind of strobe effect in your peripheral vision as you're driving along. I know my parents complained about them after they opened.