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

Bridgeport Covered Bridge

By
The Bridgeport Covered Bridge is a historic crossing of the South Fork Yuba River located in Nevada County, California near Nevada City.  The Bridgeport Covered Bridge opened as a tolled crossing during 1862 as part of the larger Henness Pass Road.  The Bridgeport Covered Bridge closed to vehicle traffic during 1972 and was recently restored during 2021.  The Bridgeport Covered Bridge is historically California's longest covered span is thought to likely be the longest such structure surviving in the world.  Featured as the blog cover is the Bridgeport Covered Bridge during 1950 when it was an active part of Pleasant Valley Road.   The history of the Bridgeport Covered Bridge The history of Bridgeport Covered Bridge was featured in the  September 1950 California Highways & Public Works .  Bridgeport Covered Bridge was constructed during 1862 over the South Fork Yuba River.  The Bridgeport Covered Bridge served as part of the Virginia Turnpike Company maintained Henness Pass Roa
Post a Comment
Read more

Former California State Route 215

By
  California State Route 215 was a short-lived state highway which existed in the Los Angeles Metropolitain area after the 1964 State Highway Renumbering.  California State Route 215 was aligned from US Route 60 at 5th Street in Pomona north to US Route 66 near Claremont via Garey Avenue.  California State Route 215 came to be after California State Route 71 was bisected in Pomona due to relinquishment of a portion of Garey Avenue due to the opening of a portion of the Corona Freeway (now Chino Valley Freeway) during 1958.  California State Route 215 was deleted by the Legislature during 1965. The history of California State Route 215 The initial segment of what was to become California State Route 215 was added to the State Highway System as part of the 1909 First State Highway Bond Act.  The First State Highway Bond Act defined what would become  Legislative Route Number 19  (LRN 19) as running from Claremont to Riverside.  The segment of LRN 19 between Claremont and Pomona would in
Post a Comment
Read more

US Route 70 over San Augustin Pass

By
San Augustin Pass is a gap in the Organ Mountains, San Augustin Mountains and San Andres in Dona Ana County east of Las Cruces.  San Augustin Pass lies an elevation of approximately 5,600 feet above sea level and was originally traversed by New Mexico State Route 3.  US Route 70 would be realigned over San Augustin Pass during 1934 when it was extended to Los Angeles, California.  During 1963 US Route 82 would be extended through San Augustin Pass to Las Cruces.  Since the early the early 1990s signage of US Route 82 has been withdrawn to Alamogordo.  San Augustin Pass and US Route 70 are largely known for the numerous closures due to test firings originating from the White Sands Missile Range.   Part 1; the history of highway designations over San Augustin Pass San Augustin Pass traditionally has been the easiest from the Rio Grande in Las Cruces east to the Tularosa Basin.  The terrain conditions at San Augustin Pass allowed for an easy crossing in the gap between the Organ Mountains
Post a Comment
Read more