Since work began on June 25, 2025, on the Arizona Department of Transportation's (ADOT) $600 million Interstate 10 between Kino Country Club Road Project southeast of downtown Tucson, crews from Sundt Construction and Jacobs have engaged in median embankment, abutment construction and utility relocation operations.
The initiative's goal is to reduce delays and enhance safety.
"ADOT initiated the project in this rapidly growing part of Tucson to address traffic capacity and congestion, improve safety, increase traffic flow," said Garin Groff, an ADOT spokesperson, "and improve two traffic interchanges Kino Parkway and at Country Club Road. The new freeway and interchange configurations will also promote safety with auxiliary lanes that will allow for additional merging space."
Sundt expects to complete work sometime in 2028.
ADOT photo
The largest highway construction project in southern Arizona history is reconstructing and widening a 3-mi. section of I-10 between Kino Parkway and Alvernon Way from two lanes to three lanes in each direction, with auxiliary lanes; reconstructing the interchange at Kino Parkway; constructing a new interchange Country Club Road to provide access for traffic that uses the interchange at Palo Verde Road to allow for safer traffic movements to and from I-10; removing the existing interchange Palo Verde Road; and constructing a new westbound on-ramp at the Alvernon Way interchange and an I-10 undercrossing to connect the North and South Kino Sports Complex.
Reconfiguration Ahead
Work includes reconfiguring the nonstandard ramp configuration at the two interchanges to construct more traditional diamond interchanges. Also, ADOT is closing an existing interchange at Palo Verde Road due to its proximity to another interchange at Alvernon Way.
A new interchange at Country Club Road will promote safety and a better flow of traffic by providing more space from the Alvernon interchange to the east.
I-10 is the sole east-west interstate serving Tucson, a rapidly growing metro area of 1 million, and the rest of southern Arizona. Average daily traffic counts range from about 95,000 near the west end of the project at Kino Parkway to 75,000 at the east end near Alvernon Road.
The project will feature a relatively new type of interchange for southern Arizona: the diverging diamond.
"ADOT chose this design for Kino Parkway and I-10 over a traditional diamond interchange (DDI) based on traffic patterns, traffic volumes and safety," Groff said. "This will be only the second diverging diamond interchange in southern Arizona, following the completion of the I-10/Houghton Road DDI that opened 10 miles to the east in 2021."
According to ADOT, "the project is the first to result from a study completed in 2020 that recommended how to best improve mobility along a roughly 10-mi. stretch of I-10 from Interstate 19 to Kolb Road."
Jacobs, the lead design firm, is designing the project.
ADOT photo
"The biggest challenge was to find out how to build the project while maintaining traffic," said Matthew Szpak, Sundt's senior project manager/project engineer. "There are 15 bridges, and we have to keep traffic open on I-10 at all times. We have a structure that goes over I-10, so there are some logistical issues with that. The biggest challenge was figuring out the phasing in an effort to keep traffic flowing for the whole life cycle of the project."
The bridges will have a 60-plus-year lifespan, and the concrete lanes will last more than 40 years.
Coordination Key
The ongoing design process sets the tempo for the work performed.
"It goes hand-in-hand," Szpak said. "The construction team is involved in the design meetings and performing constructability reviews, identifying things we like and don't like. We propose different options — how we build something might be different from what they propose.
"With design still ongoing, we've only had limited packages being released at certain points in time. We actually got an early start, setting up yards and getting some of the precursor work out of the way and setting up water tanks. Construction started on the Alvernon westbound on-ramp, which facilitated the closure of the Palo Verde westbound ramps to facilitate safer traffic movements during phase two."
Ramping Up
Crews started building a ramp from Alvernon to I-10, an element completed on Sept. 9.
"It's generally civil work — some embankment and barrier, curb and gutter asphalt paving and a little bit of drainage," Szpak said. "We call this first phase the ready-up phase.
Much of the work will occur in the median area where the new lanes are being constructed, as are eight bridges. In this phase, half of the bridges are being constructed and approximately 28,000 yds. of concrete paving will be placed.
Bringing in equipment is no cakewalk.
"Phase two is the most difficult," Szpak said. "Our access into the median isn't ideal. We left ourselves a 12-foot construction lane on the inside of the barrier, so it is possible for light-duty equipment to travel from one end to the other. Most of our equipment is delivered on flatbeds at night with a rolling slowdown. We have one gap in the barrier for the equipment to access the work site."
Phase one was a bottom-up operation.
"We started with our drainage," Szpak said. "Once in, we started on embanking, fine grading the road, getting ready for curb and gutter, and barrier — whatever the treatment is for the edge of the road, and asphalt. We're not starting on the concrete paving until all the bridges are done. We set ourselves up to go from one end to the other without having to transport paving equipment around each of the bridges."
Much of Sundt's fleet consists of Cat equipment. Phase 1 has operators using D5 and D6 dozers, 938 and 950 loaders and a bunch of excavators — 323s, 349s and 354s. Later, operators will use cranes and scrapers.
The median is essentially a ditch.
"We're embanking it with dirt and, once we get it filled to subgrade, we will fine grade and get ready for asphalt," Szpak said.
Over the next 12 months, Sundt's focus is building up the grade in the median and constructing all substructures for the 15 new bridges and the superstructure for all the median bridges.
"We have two concrete crews," Szpak said. "One crew is starting on the first abutments. They will go down the line, and the second crew is coming in building piers. We have abutments going in on I-10 over Ajo, which has already started. And once we have some crews freed up, we'll also begin work on building the new diamond diverging interchange over Country Club Road."
There are only three utility issues.
ADOT photo
"We have an existing water line on Country Club Road that Tucson Water has subcontracted to a JOC contractor to relocate," Szpak said. "They started in early September. We have an overhead power line that needs to be extended to maintain our minimum clearance over I-10, and there is a sewer in Irvington that is within 2 feet of our drill shafts. We are fortunate that there are not a lot of existing utilities that impact our work."
Getting Phased
In all there are four phases.
Phase 1 was the ready-up phase. Phase 2 covers all the median work, which is occurring in a 70-ft. wide area.
When the new lanes are built, traffic will be switched to them so that the work on Phase 3 can start, which is reconstructing the outside portion for the stretch of highway within the project limits and dealing with demo of the existing roadway, embankment of the new roadway, construction of the outside portion of all mainline bridges, construction of the Kino and Country Club DDIs and main line paving. Phase 4 focuses on cleanup, landscaping and tying everything together.
"There are a couple of tricky areas like Kino over I-10 where we have to shift traffic around to set each span over the I-10," Szpak said. "We have one span over the eastbound lanes, so we'll shift everyone over to the westbound side. Then do the same thing for westbound. The construction of the Kino diverging diamond intersection requires some unique traffic switches, but the bulk of the work is on the main lines."
The concrete main lines have 14 in. of concrete paving on 4 in. of asphalt, while the DDI lanes and ramps will have 11 in. of wide paving on 4 in. asphalt.
The maximum length of the new bridges is 150 ft., with some having drill shafts and others spread footings.
The turn-off ramps at the Palo Verde interchange are being eliminated.
"There will be no on-ramps on Palo Verde," Szpak said. "We're moving them down to Country Club Road, and we're rebuilding new bridges over Palo Verde on I-10."
Beating the Heat
Placing concrete in Arizona is no simple task.
"We don't pour a ton of concrete during the day over the summer in Arizona," Szpak said. "It's just too hot. All of it happens at night. During the winter, we'll try to pour during the day, but a lot of the bridge structures, especially the superstructure, will be poured at night because we'll need lane closures to facilitate that."
For the roadwork, operators are using loaders, dozers, skid steers, excavators, scrapers, backhoes and compactors and, for the bridge work, forklifts, cranes and manlifts.
There are 60 Sundt and subcontractor employees on site, which will increase to 70-80 as the project ramps up.
Subcontractors include Stinger Bridge & Iron, Serrano Painting, Alta Land Survey, Ammex Rebar Placers, Antigo Construction, BrightView Landscaping, Brown and White, Buesing Corp., Cactus Asphalt, Dynamic Fencing and Fabrication, E.R. Hawkins, Franklin Striping, Hardy Hole Drilling, MGM Sweeping, Miura Contracting, Outdoor Systems Management, PACE Electrical Contractors, RGG United, AWP Safety and WSP.
New materials to be brought in include approximately 100,000 yds. of white paving, 88,000 tons of asphalt, approximately 60,000 yds. of concrete, 10,000 linear ft. of concrete storm drain and 24,000 linear ft. of metal and HDPE pipe.
Excavation and demolition should generate 500,000 cu. yds. of material. CEG
