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

US Route 101 in Benbow, Garberville and Redway

By
The communities of Benbow, Garberville and Redway can all be found along US Route 101 within southern Humboldt County.  The former surface alignment of US Route 101 in Garberville and Redway once crossed the Garberville Bluffs along what is now Redwood Drive via a corridor constructed as part of the Redwood Highway during the 1910s.  US Route 101 through Benbow, Garberville and Redway was modernized by 1935.  US Route 101 would eventually be upgraded to freeway standards in Benbow, Garberville and Redway by extension of the Redwood Freeway during 1966-68.  As the cover photo the original grade of US Route 101 and the Redwood Highway can be seen at the Garberville Bluffs during 1934.  US Route 101 can be seen in the communities of Benbow, Garberville and Redway on the 1935 Division of Highways Map of Humboldt County .   The history of US Route 101 in Benbow, Garberville and Redway Benbow, Garberville and Redway lie on the banks of the South Fork Eel River of southern Humboldt County.  D
Post a Comment
Read more

Patterson Pass Road

By
Recently on a day trip to the San Francisco Bay Area I traversed the Diablo Range eastbound via Patterson Pass Road. Patterson Pass Road is an approximately 13 mile roadway which starts at Mines Road in Livermore of Alameda County.  Patterson Pass Road eastward ascends over the approximately 1,600 foot namesake Patterson Pass into San Joaquin County where it ends at Interstate 580 near Tracy.  Patterson Pass Road has an infamous reputation as being a dangerous roadway due to the lengthy one-lane section and heavy rush-hour commute traffic. Patterson Pass is one of the earliest documented European paths of travel over the Diablo Range as it was explored during the 1775-1776 Spanish Expedition led by Juan Bautista de Anza.  The 1775-1776 Spanish expedition charted out much of San Francisco Bay which led to the founding of the Presidio of San Francisco and Mission San Francisco de Asis.  Patterson Pass Road between Cross Road east to Midway Road is part of the Juan Bautista de Anza
Post a Comment
Read more

Highways in and around Old Sacramento; US 40, US 99W, CA 16, CA 24, CA 70, CA 99, CA 275, and more

By
This past weekend I was visiting the City of Sacramento for a wedding.  That being the case I decided to head out on a morning run through Old Sacramento, Jibboom Street Bridge, I Street Bridge, Tower Bridge, and path of US Route 40/US Route 99W towards the California State Capitol.  My goal was to retrace the paths of the various highways that once traversed the Old Sacramento area. This blog is part of the larger Gribblenation US Route 99 Page.  For more information pertaining to the other various segments of US Route 99 and it's three-digit child routes check out the link the below. Gribblenation US Route 99 Page The old highway alignments of Sacramento The City of Sacramento lies at the confluence of the Sacramento River and American River in Sacramento Valley.  Sacramento Valley was discovered by Spanish Explorer Gabriel Moraga in 1808.  Moraga referred to the fertile Sacramento Valley akin to a "Blessed Sacrament."  By 1839 John Sutter Sr. settled in Mexican held
Post a Comment
Read more