Future I-685 from Carolina Core website Future I-685 - Central Carolina Freeway

First Proposed:  2017
Route Approved:  2022 (by AASHTO) 2023, (by FHWA)

First Future Signs Placed along US 421:  2024
To be signed as I-685:  ??

The Route: US 421 from I-85 in Greensboro to I-95 in either Dunn or  (via NC 87 at Sanford and I-295) Fayetteville, ~ 90 miles


First proposed by economic developer, Jed McMillan on behalf of the Piedmont Triad Partnership (PTP) to the NCDOT Board on August 3, 2017 in Greensboro to attract more businesses to the region. His new interstate freeway would travel an upgraded US 421 between Greensboro and Fayetteville connecting 4 business 'megasites' (the Aerospace Center at the PTI Airport in Greensboro, the Greensboro-Randolph County project near Liberty, the Chatham Advanced Manufacturing site in Siler City, and the Moncure Megasite on US 1 in Chatham County). The NCDOT Board took no position on the proposal at the time, nor did the Board Chair Mike Fox. Though he did comment that parts of US 421 would not be too hard to upgrade to an Interstate.1 In 2018, in an effort to attract more partners in areas throughout central North Carolina, the PTP rebranded itself as the Carolina Core and launched efforts to convince government and business leaders along the US 421 corridor between Greensboro and Fayetteville to lobby NCDOT about designating the highway an interstate. As of 2024 19 counties are using the Carolina Core name to market economic opportunities and the group has gotten over $20 billion in planned capital investments.2 Here's a map of the Carolina Core region from the group's website, notice the emphasis on US 421 all the way to Winston-Salem, they are also lobbying for US 421 between I-40 in Winston-Salem and I-77 become another interstate, I-777, they hope to have legislation for that route in Congress in 2025:

Image of NC Core business marketing region and emphasis on US 421 (Future I-685), NC Carolina Core, 2024

On September 25, 2019, the Greensboro Urban Area Metropolitan Planning Organization (GUAMPO) approved a resolution in support of giving US 421 interstate designation and bringing it up to interstate standards from Greensboro either to Dunn or Fayetteville, using the NC 87 corridor south of Sanford. The resolution notes that US 421 connects I-95 with I-40 and would provide a “valuable alternate route for military and freight traffic” between the 2 cities as well as “additional evacuation routes and relief and recovery routes to the region.” The resolution noted that the NCDOT Board of Transportation had already passed its own resolution in support of upgrading US 421 between I-40 and I-95 to an interstate. Other MPOs along the corridor approved similar measures between 2019 and 2021.3

The infrastructure bill signed into law by President Biden in November 2021 contained, among its many provisions, text added by NC Senators Richard Burr and Thom Tillis making US 421 from I-85 in Greensboro to I-95 in Dunn a 'High Priority Corridor.' This would be the first step in asking for a Future Interstate designation along the route, or part of the route.4 The supporters of this corridor chose I-685 as its proposed number in early 2022. In its Spring 2022 meeting, AASHTO approved the Future I-685 designation, pending FHWA concurrence. FHWA concurrence was not publicized but was apparently granted in late 2022 or 2023.

On May 20, 2024 NC officials and members of the Carolina Core organization gathered at the newly completed bridge over US 421 (see photos below) near the Future Toyota plant in Julian and displayed Future I-685 signs that will be put up along US 421 between Greensboro. There was no announcement as to when improvement projects would start to enable the future route to become an actual interstate. Here's one of the signs displayed:5

Image of new Future I-685 sign being displayed at NC Core event on 
                                                                            US 421 in Julian, May 2024

Here's a map of the potential corridor published by the Triangle Area Rural Planning Organization (TARPO), a voluntary association of local governments in Chatham, Lee, Moore, and Orange Counties, on November 18, 2021. Notice the indecision as to whether the route should follow US 421 all the way to I-95 or head south to Fayetteville via NC 87, though an article on the May 20 sign unveiling discussing the difficulties of upgrading parts of US 421 south of Sanford seem to indicate the US 421 route to Dunn:

Image of map of planned I-685 corridor from TARPO transportation planning organization, November 2021

A later alternative map published in 2024, possibly by NCDOT, showed 3 possible alternative corridors for I-685 south/east of Sanford:

Image of map of I-685 south of Sanford alternative, possible by NCDOT, 2024

Alternative A would follow the US 421 corridor to Dunn with portions, especially the segment linking to I-95 on a new alignment.

Alternative B would initially follow the NC 87 corridor then on a new alignment between Swann and I-295 near Spring Lake, then using I-295 to access I-95.

Alternative C would mostly follow the NC 87 corridor to I-295 near Fort Liberty (formerly Fort Bragg), then using I-295 to access I-95.

It is unknown whether any of these alternatives are 'official' or if any studies about their costs and benefits have been funded.

Alternative C would require little new road construction but would require upgrades of the existing NC 87 roadway. If I-685 is signed along a portion of I-295 it would make it the third two 3-digit interstate concurrency in North Carolina (I-785/I-840, I-587/I-795). There is only 1 other one in the rest of the country, I-680/I-271 in Cleveland.

There are currently no projects, besides those related to the Toyota Plant, Project C204702 as of April 30, 2024 66.5% complete with a revised completion date of August 14, 2024,6 funded in the 2024-2033 STIP to improve US 421, or other possible routes, to interstate standards. A Future Interstate designation typically allows for 30 years time before the interstate must be completed.


Google Maps Street View images along US 421 near Julian from September 2023:

Image of new bridge being built for new exit to serve Toyota plant from US 421 North in Julien, 
          Google Maps Street View, September 2023

View of new bridge being built for new exit to access Toyota Battery plant in Julian as seen from US 421 North.

Image of new sign advertising NC Crossroads business corridor on US 421 South in Julien, 
          Google Maps Street View, September 2023

Sign advertising NC Carolina Crossroads/NC Core Megasite along US 421 South prior to the new exit for the Toyota Battery plant.

Image of new off-ramp being built for new exit to serve Toyota plant from US 421 South in Julien, 
          Google Maps Street View, September 2023

US 421 South approaching the new ramp to access the Toyota Battery plant still under construction.

Image of new bridge being built for new exit to serve Toyota plant from US 421 South in Julien, 
          Google Maps Street View, September 2023

View of future off-ramp for new exit to access Toyota Battery seen prior to the bridge on US 421 South.

Image of new bridge being built for new exit to serve Toyota plant from US 421 South in Julien, 
          Google Maps Street View, September 2023

View of new interstate standard bridge being built for the Toyota Battery plant from US 421 South. The bridge was completed in May 2024.