Skip to main content

Remaining stretch of I-485 will feature three unique types of interchanges

Image
By
The remaining 5.4 miles of I-485 currently under construction in Mecklenburg County will feature three unique interchanges.  All three are in use elsewhere within the country, but would be the first ones built in the Tar Heel State.

At two of the interchanges, the new designs are considered upgrades (in traffic flow and cost savings) versus what had originally been planned.

The interchange design names are Split Diamond, Diverging Diamond, and Turbine.

Heading East from the current terminus at NC 115, the three new interchange designs run as follows:

The Split Diamond interchange will be located at Prosperity Church Road.  This interchange will consist of two access roads and six roundabouts.

Split Diamond Interchange with Prosperity Church Road (NCDOT)
The Diverging Diamond Interchange (DDI), first used in Missouri, is starting to catch interest in North Carolina.  The interchange design, actually reverses the lanes of traffic on the surface/cross street.  This will be located at the Mallard Creek Road exit on I-485.

This design replaces a planned Single Point Urban Interchange (SPUI) for 485 and Mallard Creek.


We covered a Diverging Diamond Interchange back in October when NCDOT announced it is considering the design on NC 133 where it meets the US 74/76 freeway in Leland.  These two intersections, along with two more on nearby Interstate 85 at NC 73 and Poplar Tent Road, are some of seven prospective locations for this new style of interchange.

Finally, the Turbine - an interchange that has all left turn movements circling around a central bridge in a clockwise direction, creating a seamless movement between the two highways.  This replaces the previously planned four-level stack interchange.  (Similar in design to where I-77 and 485 meet in Southern Mecklenburg County.)

The new "Turbine" interchange at 85/485.  (NCDOT)      
According to NCDOT, this type of interchange will cost less to build and maintain, take up less space, and allow for less interruptions to existing I-85 traffic during construction.


Story Links:
Last Outerbelt juntions to display unique functions ---Charlotte Observer
I-485 Charlotte Outer Loop ---NCDOT
Labels:

Comments

Froggie said…
NCDOT apparently doesn't see it as such, but I-40/Exit 195 (at NC 109) in Winston-Salem, is very much a split-diamond.
9:53 PM
Anonymous said…
Should that be counterclockwise, or am I missing something? (Maybe clockwise in countries that drive on the left...)
11:37 AM
Douglas Andrew Willinger said…
Reminds me of my Alexandria Orb proposal:

http://wwwtripwithinthebeltway.blogspot.com/2007/02/alexandria-orb-page-one-news-december.html

http://wwwtripwithinthebeltway.blogspot.com/search/label/Alexandria%20Orb
8:01 PM
Post a Comment

Popular posts from this blog

What's In a Name?: When the Roads Really Do Tell a Story

By
  Our tagline on the Gribblenation blog is "because every road tells a story". Some roads tell different stories than others. Along our travels, we may see historic markers that tell us a little story about the roads we travel or the places we pass by. Some historic markers are more general, as to telling us who lived where or what old trail traversed between two towns. During my travels across New York State and other states or provinces, I pass by many historic markers, some with interesting or amusing references to roads. I wanted to highlight a few of the markers I've seen along my travels around the Empire State and help tell their stories. Those stories may be as specific as explaining the tales of a tree that was used to help measure a distance of eight miles from Bath to Avoca in Steuben County, as referenced on the Eight Mile Tree historical marker above. They may also help point the way along historical roads first used centuries ago, or may help tell a local l...
Post a Comment
Read more

2018 Mojave Road Trip Part 2; The deadly desert highway (California State Route 127 and Nevada State Route 373)

By
After leaving Barstow via Old Highway 58 my next destination was in Death Valley.  To access Death Valley from rural San Bernardino County required a trek on north on Interstate 15 to California State Route 127 which becomes Nevada State Route 373 at the state line. Along I-15 I encountered the road sign oddity that is Zzyzx Road about eight miles south of Baker.   Zzyzx Road is a four mile road that used to go to the Zzyzx Mineral Springs and Health Spa.   The spa was founded in the 1940s and the owner made up the name "Zzyzx" to claim it was the last word in the English Language.  The spa has been shut down since the 1970s and is now part of a Desert Studies Center for California State University. The southern terminus of CA 127 in Baker is located at I-15 exit 246.  CA 127 is a 91 mile north/south highway which runs to the Nevada State Line in Inyo County.  CA 127 is called Death Valley Road from I-15 northward.  South of CA 127 ...
4 comments
Read more

May 2023 Ontario Trip (Part 3 of 3)

By
  Over the years, I have made plenty of trips to Ontario, crisscrossing the southern, central and eastern parts of the province. Living in Upstate New York, it's pretty easy to visit our neighbor to the north, or is that our neighbor to the west? Ottawa is one of my favorite cities to visit anywhere in the world, plus I've discovered the charm of Kingston, the waterfalls of Hamilton (which is on the same Niagara Escarpment that brings us Niagara Falls), the sheer beauty of the Bruce Peninsula, and more. But I hadn't explored much of Cottage Country. So I decided to change that, and what better time to go than over Memorial Day weekend, when the daylight is long and I have an extra day to explore. On the third and final day of my trip, I started in Huntsville and made my way through Muskoka District and Haliburton County, passing by many lakes along the way. I stopped in towns such as Dorset, Haliburton and Bancroft before making a beeline down to Belleville and then over th...
Post a Comment
Read more