Crossing the Finish on S.T. Wooten’s I-40 Overhaul in Raleigh
BY Matt Davis
Completed interstate in Eastern North Carolina offers milestone for S.T. Wooten
While S.T. Wooten crews knew the I-40 road widening project was going to be expansive, nobody could have guessed just how far it would take them. The project already marked a milestone as the biggest in company history when construction kicked off in 2018, but new initiatives combined with Raleigh’s fast growth brought adjustments that added extra years of work to the scope.
After the project was underway, the North Carolina Department of Transportation (NCDOT) was challenged to address additional traffic concerns along Jones Sausage Road from a new Amazon distribution center, which S.T. Wooten also worked on.
S.T. Wooten’s I-40 project was initially scoped as a four-year, $360 million job, but expansions added an extra $60 million to the budget along with two additional years of construction. The project will be reaching completion this fall as crews put the finishing touches on years of hard work and dedication.
Enhancements to the plan
The purpose of the I-40 project was to improve traffic conditions through a busy 13-mile stretch—extending from the I-440 divide in Raleigh to 2 miles east of the N.C. 42 interchange in Johnston County—with two new lanes added in each direction. Construction also involved a total of 15 bridges being built or revamped, along with the installation of two diverging diamond interchanges (DDIs).
After the project was underway, the North Carolina Department of Transportation (NCDOT) was challenged to address additional traffic concerns along Jones Sausage Road from a new Amazon distribution center, which S.T. Wooten also worked on. The NCDOT took swift action and with recommendations from their engineers, decided to retrofit a DDI across the existing bridge that crosses I-40 to help with congestion. That’s just one example of how the NCDOT was flexible in making accommodations for the developing area to better help the traveling public.
Crews from S.T. Wooten handled nighttime and day paving to complete different portions of the project as it developed and expanded over the years.
Diverging diamonds
The first DDI crews tackled for the I-40 project was positioned at the 40/42 area, which is where Highway 42 crosses over I-40. To accommodate the DDI, two new bridges were constructed with the roads widened on either side of the bridge. The new pattern was put in place during the spring of 2024.
For construction on the DDI at Jones Sausage Road, the process was unique since it was built utilizing the existing bridge. Work included:
- Tearing down existing barrier rail and adding sidewalk and 3-bar metal rail
- Installing new latex deck overlay
- Installing a median barrier to separate traffic
In the fall of 2023, the intersection was put into a temporary single-lane DDI pattern. Crews had to pave the first lift of surface then adjust and activate new signals for the pattern over a single weekend. Once in this pattern, there was a 28-day timeline to complete the median barrier and islands before opening to a full pattern. Crews successfully opened into the full pattern on the weekend before Thanksgiving in 2023.
A 280-foot-long conveyer handled about 169,000 tons of asphalt, saving crews about 8,500 truckloads entering and exiting traffic.
Asphalt conveyer comes in handy
Faced with constant traffic surrounding the I-40 work zone near Clayton, S.T. Wooten engineered a unique asphalt conveyor to help streamline hauling processes for crews. The solution helped move asphalt safely from the Astec double barrel plant, over the highway, and into an 85-ton Gencor silo in the median-area work zone. From there, dump trucks were able to transport the asphalt to onsite paving equipment without having to haul through traffic and impact the traveling public.
The plant had two 300-ton silos and was rated for 350 tons per hour. The team produced multiple mixes for the project—the average load out temperature was 300 degrees for standard B and C mixes utilizing 64-22, and 325 degrees for the D mixes utilizing 76-22 asphalt cement.
After the project was underway, the North Carolina Department of Transportation (NCDOT) was challenged to address additional traffic concerns along Jones Sausage Road from a new Amazon distribution center, which S.T. Wooten also worked on.
We used Astec’s Weighmate system for controls and ticketing; communication among our team members was excellent. Between the plant control house, median control house, as well as the person controlling the trucks dumping for transfer across the conveyor, we used handheld radios. We also used red and green lights operated by the median control house to make sure the hopper and belt weren’t overloaded when the trucks were dumping.
The approximately 280-foot-long conveyer offered benefits to both crews and drivers. The system:
- Handled about 169,000 tons of asphalt, transporting it through an enclosed conveyor belt over the highway.
- Prevented dump trucks from needing to merge in and out of traffic while working. This ended up saving crews about 8,500 truckloads entering and exiting traffic.
- Reduced the total number of trucks and fuel needed to run the project. A single truck only has to drive around 100 yards to move the asphalt from the plant to the conveyer. Compare this to a 20-mile round trip that might be required without the conveyer.
While it was a unique structure, S.T. Wooten has used the asphalt conveyor approach before—about a dozen years ago on a separate stretch of I-40.
The Astec double barrel plant had two 300-ton silos and was rated for 350 tons per hour.
Bifurcated slope creates efficient split
Like most large highways, I-40 has a split between the eastbound and westbound lanes. To accommodate construction, a tall barrier wall was installed the full length of the median and in some areas with the roadway positioned at different elevations. This was done to ensure crews could adjust the profile of the roadway to accommodate the additional lanes.
That difference in elevation, also called a “bifurcated” slope, was successful in allowing each direction of I-40 to have necessary variation and reduce the amount of cut or fill dirt needed. Using this bifurcated setup also made it easier to split off the ‘collector’ and ‘distributor’ lanes that people use for entering and exiting the highway, which was important in helping ease the flow of traffic in the NC-42 and newly added Cleveland Rd. interchange.
Strategic planning and close communication between crews and subcontractors was instrumental in staying on schedule with so many moving parts across the I-40 job.
With the additions considered, the number of lanes throughout the length of the entire project varies from 12 lanes (six in each direction) to six lanes (three in each direction) and due to the very wide pavement section and the curvature of the road the bifurcation was required.
Making the Shift on S.T. Wooten’s I-40 Road Widening Project
Strategically overcoming setbacks
While traffic was the most consistent challenge for crews on I-40, other obstacles came up as they do with any project. The pandemic, employee turnover and bad weather all threw a wrench into plans at times. Traffic shifts were also a unique element to manage and execute – since crews were on a tight turnaround to complete the paving and grading before traffic had to be re-opened with each transition.
Strategic planning and close communication between crews and subcontractors was instrumental in staying on schedule with so many moving parts across the I-40 job. Experience was also an asset for the team, as S.T. Wooten has now worked with the NCDOT on numerous large road construction projects – including a similarly expansive overhaul taking shape on I-95 near Fayetteville.
End of a journey
The I-40 project wouldn’t be reaching its completion date without the significant progress made by crews this past year. Crews have been working diligently to finish the surface and complete the punch list for the final stretch running from 70 bypass to Cornwallis Road. Extending 4 miles, that covers roughly a third of the total project. Final touches will also include wrapping up construction at NC42, Cleveland Road and Rocky Quarry Road.
While the team is excited to finally cross the finish line, lessons learned from the project will be invaluable for future jobs. One such thing is the ability to adapt to changing conditions and situations. We go into these projects with a very detailed plan and schedule, but being flexible to make adjustments as you move forward—even if it’s not what you initially had in mind—is key to success.
To accommodate construction, a tall barrier wall was installed the full length of the median and in some areas with the roadway positioned at different elevations.
Hundreds of crew members had a hand in construction on the I-40 project over the past six years. They should be proud of their work and a successful product that commuters will be grateful for in Wake and Johnston County’s growing communities.
Matt Davis is a division manager for S.T. Wooten Corporation. He shared, “Our hearts are with all the individuals and communities affected by Hurricane Helene, which unfolded as this article was going to press. We stand in solidarity with everyone impacted, and we are committed to supporting recovery efforts during this challenging time.”