AARoads Forum

National Boards => General Highway Talk => Topic started by: johndoe on November 06, 2018, 06:31:48 PM

Title: Loop ramp INSIDE another loop ramp?
Post by: johndoe on November 06, 2018, 06:31:48 PM
Have you ever seen an interchange with two cloverleaf style loop ramps (270 degrees) from and to the same spot?   :pan:

Something like this:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Foi66.tinypic.com%2Feuewbp.jpg&hash=837199c62fd9f1dbb788245322bb109c506a6b13)

At work today a coworker showed me a picture of such a thing and we were trying to figure out why it might exist.  It looked like the bridges had enough width that the extra loop had lanes...The picture came from the 1965 Highway Capacity Manual where it showed aerial images of this location throughout the day, demonstrating LOS.  I might have to try to get a picture tomorrow.

I'm just hoping to find some on Google maps to figure out what the deal is.
Title: Re: Loop ramp INSIDE another loop ramp?
Post by: kphoger on November 06, 2018, 06:33:21 PM
You're sure it wasn't just that new loop ramps were constructed and the old ones hadn't yet been demolished?
Title: Re: Loop ramp INSIDE another loop ramp?
Post by: NE2 on November 06, 2018, 06:38:31 PM
HOV ramps to bypass ramp meters?
Title: Re: Loop ramp INSIDE another loop ramp?
Post by: NE2 on November 06, 2018, 06:59:08 PM
http://onlinepubs.trb.org/Onlinepubs/sr/sr87.pdf pp. 110-111. Those are sidewalks at I-678 and the Belt Parkway. Conduit Avenue (the Belt frontage roads) has sidewalks, and those loops allowed foot traffic to cross the Belt. The grading appears to still exist at least for the one in the northeast corner (the current overgrown pathway is on a different alignment).

Title: Re: Loop ramp INSIDE another loop ramp?
Post by: johndoe on November 06, 2018, 08:22:26 PM
Quote from: NE2 on November 06, 2018, 06:59:08 PM
http://onlinepubs.trb.org/Onlinepubs/sr/sr87.pdf pp. 110-111. Those are sidewalks at I-678 and the Belt Parkway. Conduit Avenue (the Belt frontage roads) has sidewalks, and those loops allowed foot traffic to cross the Belt. The grading appears to still exist at least for the one in the northeast corner (the current overgrown pathway is on a different alignment).

Winner winner!  I even searched for the document and couldn't find it... and how did you realize the location?! 
https://goo.gl/maps/9qZc3QrVS1z
Title: Re: Loop ramp INSIDE another loop ramp?
Post by: kphoger on November 07, 2018, 11:46:43 AM
Quote from: johndoe on November 06, 2018, 08:22:26 PM
Winner winner!  I even searched for the document and couldn't find it... and how did you realize the location?! 

I'm pretty sure it's magic.  Black magic.  He's the king of digging this stuff up.