Bridge Piers in Roundabouts Islands

[peterj920]

On Wis 29 local in Howard, WI, a bridge pier was placed in the center of a roundabout for a system ramp between Wis 29 east and I-41 north.  There is another instance of a bridge pier in the center of a roundabout in Lincoln, NE at Salt Creek Roadway and Stadium Dr near Memorial Stadium.

https://www.google.com/maps/@40.822479,-96.7072829,3a,75y,229.47h,85.82t/data=!3m7!1e1!3m5!1shxBwt6kMawjGqEU6-M-pBA!2e0!6s%2F%2Fgeo3.ggpht.com%2Fcbk%3Fpanoid%3DhxBwt6kMawjGqEU6-M-pBA%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D261.08533%26pitch%3D0!7i13312!8i6656?hl=en

Are there any other instances where bridge piers are placed in the center of roundabouts?

[cl94]

Washington Avenue Extension at CR 156 (Fuller Road), Albany

[tradephoric]

169th & Marth Road, Bloomington, MN:

https://www.google.com/maps/@44.8580727,-93.3931378,71m/data=!3m1!1e3

[kphoger]

Isn't this pretty common for roundabout-under-highway interchanges ?
...like this one in Newton, KS...

[cl94]

Isn't this pretty common for roundabout-under-highway interchanges ?
...like this one in Newton, KS...

It is, but such interchanges are rare in this country.

[jeffandnicole]

In NJ: The Airport Circle (30/130/38) and Somerville Circle (202/206) are underneath highways with bridge piers in the middle.

The Airport Circle itself isn't much of a true circle anymore, but it still functions more/less like one, albeit with traffic lights. 

[roadfro]

Isn't this pretty common for roundabout-under-highway interchanges ?
...like this one in Newton, KS...

It is, but such interchanges are rare in this country.

In the US, I think it's more common to have a dumbbell or dogbone interchange (diamond interchange with two roundabout intersections) than to have a single roundabout. This makes for a shorter bridge above and saves money in construction costs.

[jakeroot]

Golden Ears Way, a relatively new freeway in Maple Ridge, British Columbia, passes over a roundabout. The roundabout has a ramp towards the freeway, but it's only for buses:

[cl94]

Golden Ears Way, a relatively new freeway in Maple Ridge, British Columbia, passes over a roundabout. The roundabout has a ramp towards the freeway, but it's only for buses:

What are the two-color signals for?

[jakeroot]

Golden Ears Way, a relatively new freeway in Maple Ridge, British Columbia, passes over a roundabout. The roundabout has a ramp towards the freeway, but it's only for buses:

http://i.imgur.com/P5jYG0L.png

What are the two-color signals for?

It's a train signal. There's a train crossing to the left of the image; it prevents traffic from blocking the roundabout. That said, it was only activated last year, and I've yet to see it in action. I don't really see the point. A yellow box across the entry points would do this signal's job just as well.

[paulthemapguy]

I have found interchanges like this to be quite common in Massachusetts, but the circles tend to be very large.  Example: https://www.google.com/maps/@42.2099835,-70.9953422,15.62z?hl=en

[cl94]

I have found interchanges like this to be quite common in Massachusetts, but the circles tend to be very large.  Example: https://www.google.com/maps/@42.2099835,-70.9953422,15.62z?hl=en

Ah, yes, the rotary interchange. Those things can be a flipping nightmare with the speeds people take them at.

[english si]

There's myriad in the UK - especially at roundabout interchanges like the rotary versions in MA. Here's one of the most interesting:

Though the brick viaduct here at Bushey Arches predates the invention of circular islands in the middle of junctions by about 80 years (1834-7 construction) and so the roundabout is a way of getting past the bridge piers (rather than funnel through one arch - which was the original situation) rather than the bridge piers using the roundabout to ground themselves on, but for the later parallel viaduct the use of the roundabout to plonk a support down is definitely the case.

[vdeane]

I have found interchanges like this to be quite common in Massachusetts, but the circles tend to be very large.  Example: https://www.google.com/maps/@42.2099835,-70.9953422,15.62z?hl=en

Wow, that's not even "bridge pier in roundabout" level... that's "two separate bridges to cross circle" level!

[Big John]

From last year's Madison meet, pier inside and piers outside roundabout for same bridge support: https://goo.gl/maps/7haWbTJUT7G2

[Rothman]

I have found interchanges like this to be quite common in Massachusetts, but the circles tend to be very large.  Example: https://www.google.com/maps/@42.2099835,-70.9953422,15.62z?hl=en

Wow, that's not even "bridge pier in roundabout" level... that's "two separate bridges to cross circle" level!

I prefer the circle on the northern end of US 202's crossing of the Connecticut (South Hadley side):

https://www.google.com/maps/@42.2372754,-72.6195376,11.92z

Never had any problems with it. 

Concord Rotary's smaller and causes me to have white knuckles much more often...although I've never witnessed an accident there.