16th Street Mall Rebuild in Denver Overcomes Setbacks, Fall Finish Set
By Lori Tobias CEG CORRESPONDENT
Work on a three-and-a-half year, $175.4 million project to update Denver’s iconic 16th Street Mall is more than three-quarters complete, with a target finish line of fall 2025.
Completion was set back nine months from the original schedule due to some unexpected challenges.
Those setbacks also put the project $26.4 million over the original $149 million budget but, at the same time, ultimately proved helpful when crews with design/build firm PCL Construction Services later encountered similar problems, said Nancy Kuhn, director of the communications division for the City and County of Denver Department of Transportation and Infrastructure.
“The primary construction challenge was complex
underground utilities down the transitway, all installed at different times since the late 1800s with varying levels of documentation, including a centuries-old water line, steam lines, storm and sanitary lines, electrical infrastructure, gas networks, over a dozen telecom lines and traffic networks, that are all layered underground,” Kuhn said. “We took what we learned about these various underground utilities in the first few blocks to take new steps in subsequent blocks to minimize impacts to the overall schedule.”
The 1.25-mi. 16th Street Mall opened in 1982, conceived by the city as a way of sparking life in a declining downtown. The pedestrian mall, designed by famed architect I.M. Pei, features free shuttles and connects the downtown from Denver Union Station to Civic Center Park and the Colorado State Capital.
Loop 303 Extension Among ADOT’s 2025 Phoenix Freeway Plans
The Arizona Department of Transportation is looking ahead to starting, continuing or completing construction on several Phoenix-area freeway projects in 2025.
Topping ADOT’s list of new construction projects is an extension of Loop 303 from Van Buren Street south to Maricopa County Highway 85 (MC 85) in the Goodyear area.
The Loop 303 project, which is in final design, will provide three freeway lanes in each direction between Van Buren Street and Lower Buckeye Road and two lanes in each direction from Lower Buckeye Road to MC 85. New bridges will carry the freeway over several cross streets and the Union Pacific Railroad. The new stretch of Loop 303 will be built where Cotton Lane now carries area traffic.
Work is scheduled to start by fall 2025 and last approximately three years.
The following are among ADOT’s other major Phoenixarea freeway projects in 2025:
Completion of the I-10 Broadway Curve Improvement Project between the I-17 “Split” and Loop 202 by spring. This has been the largest freeway reconstruction project in ADOT’s history. Work started in fall 2021. Along with new lanes that already have been added along 11 mi. of I-10, crews are finishing elevated ramps providing direct connections at the I-10/State Route 143 interchange. They also will complete two pedestrian/bicyclist bridges and widening the Guadalupe Road bridge over I-10.
page 2
A Cat 325 excavator demolishes part of the original 16th Street Mall.
Paving and concrete barrier construction on northbound Loop 101.
I-10 Broadway Curve Improvement Project Begins Soon
For this project, the DB team is known as the Developer. The Developer is a joint venture of Pulice Construction Inc., FNF Construction Inc. and Flatiron Constructors Inc., known as Broadway Curve Constructors. The project designers are T.Y. Lin International Group, Stanley Consultants and Aztec Engineering.
The Loop 101 (Pima Freeway) Improvement Project between Shea Boulevard and Princess Drive/Pima Road in Scottsdale is scheduled for completion by early 2026. Work started in January 2024. The project includes the addition of a lane in each direction within a 4.5-mi. work zone. Crews also are converting the Loop 101 interchange at Frank Lloyd Wright Boulevard into a diamond configuration to improve traffic flow.
Completion of the I-17 Improvement Project between Anthem Way and Sunset Point north of Phoenix in late 2025. Work on the 23-mi. project started in fall 2022. Crews are nearing completion of third lanes in each direction between Anthem Way and Black Canyon City. Work also continues on the unique 8-mi. flex lanes system north of Black Canyon City.
The start of an I-10/Loop 101 Interchange Improvement Project in the West Valley is expected by summer 2025. Work will include construction of new HOV ramps providing I-10/Loop 101 connections to and from the east (downtown Phoenix). Crews also will modify the existing southbound Loop 101 to eastbound I-10 ramp to add a direct “exit ramp” to 91st Avenue. A new combined southbound Loop 101 exit to both Thomas and McDowell roads will be built to help manage overall freeway traffic flow. Construction is expected to last two years.
Work will advance on the Loop 101 (Agua Fria Freeway) Widening Project between I-17 and 75th Avenue in the
northwest Valley. The two-and-a half year project started in September 2024. In addition to adding new Loop 101 lanes in each direction, the project includes interchange and crossstreet improvements at 75th Avenue.
The Loop 202 (Santan Freeway) Widening Project between Loop 101 (Price Freeway) and Val Vista Drive in the southeast Valley, which started in August 2024, will add new lanes in each direction. Bridge and interchange improvements also are underway. The project is scheduled for completion by early 2027.
Construction of new I-10 Gila River bridges southeast of Riggs Road will advance during 2025. Crews started work in summer 2024 to replace the outdated existing I-10 bridges
crossing the Gila River. Completion is scheduled by summer 2026.
Completion of the I-17 Resurfacing Project between Happy Valley Road and State Route 74 in north Phoenix by March 2025. The project, which started in May has included diamond grinding of the freeway’s concrete pavement surface. ADOT also is finalizing plans for an I-17 resurfacing project between SR 74 and Anthem Way, scheduled to start by summer 2025.
ADOT plans and constructs new freeways, additional lanes and other improvements in the Phoenix area as part of the Regional Transportation Plan for the Maricopa County region. Many projects are funded in part by Proposition 400, a dedicated sales tax approved by Maricopa County voters in 2004. Voters in November approved Proposition 479, extending the existing half-cent tax to fund future transportation projects in the Phoenix region.
(Photos courtesy of the Arizona Department of Transportation.)
Construction Starts On New I-40 Interchange in Kingman
Construction is under way on a new Interstate 40 interchange in Kingman, Ariz., ktar.com reported.
The Rancho Santa Fe Parkway interchange will be about 4 mi. east of the existing Route 66 interchange at Andy Devine Avenue and is designed to improve accessibility around the Kingman Airport.
Fisher Sand & Gravel Co., of Tempe, Ariz., serves as the $106 million project’s lead contractor.
The city of Kingman will separately construct Rancho Santa Fe Parkway.
The interchange project involves constructing a new system-to-system traffic interchange at the junction of Interstate 40 and U.S. 93 in West
Kingman and Mohave County, according to the Arizona Department of Transportation (ADOT).
The project includes adding a new U.S. 93 segment that connects directly to I-40. Excavation work to build the new roadway is under way (U.S. 93 west of city limits), creating a freeflowing connection between I-40 and U.S. 93 without having to stop at a traffic signal, constructing new connector ramps at U.S. 93 to maintain access to Beale Street sand increasing capacity on I-40 and accommodating traffic for at least the next 20 years.
By the numbers, the project will include, according to ADOT, 6 mi. of new road construction, five new
bridges, two bridge widenings, four bridge rehabilitations, 13,000 cu. yds. of concrete, 2.6 million lbs. of reinforced steel, 2 mi. of sound walls and 600,000 cu. yds. of excavation.
(All photos courtesy of the Arizona Department of Transportation.)
Interstate 40 near Kingman, Ariz.
The milling of the northbound Loop 101 near Princess Drive/Pima Road.
ADOT from page 1
Mall Redo Includes New Granite Pavers, 50 More Trees
According to the Denver Mile High City webpage, “The mall offers Denver's best people-watching. There are 42 outdoor cafés along the mall, making it the perfect place to grab a bite to eat or have a drink. Denver Pavilions, near the south end of the mall, is a shopping and dining complex with 12 movie theaters and more than two dozen shops and restaurants. At the north end of the mall, 16th Street continues as a pedestrian path over three bridges connecting downtown to Common Park and LoHi, a hip neighborhood filled with restaurants and brewpubs.”
But the 40-year-old mall has experienced problems for years, prompting talks more than a decade ago on how to revive the maintenance-plagued city street. The revitalization, the first full makeover since the mall’s opening, began in 2022.
“A primary driver for the project was the need to address deteriorating infrastructure, specifically the granite paver system, that was resulting in poor drainage, frequent disruptions to the transit system and maintenance costs of more than $1 million annually,” Kuhn said.
The problem likely evolved from the design of the original pavement system which did not provide drainage for water that seeped into the mortar base below the granite pavers. Water became trapped, loosened the granite pavers during freeze-thaw cycles and, over time, the pavers began to break.
The new transit lane pavers are approximately 8-by-8 in., or four pavers for every one of the original-sized pavers. In the pedestrian area, pavers are 4-by-8 in., or about eight new pavers for each originalsize paver.
“The smaller paver size spreads the wheel loads better to the mortar and grout bed and holds up better over time,” Kuhn said. “The
smaller 4-by-8 brick pattern pavers are part of a sand set system in the pedestrian area where the pavers interlock. The smaller size of the new granite pavers, along with the modified drainage system, and different grout and mortar materials, all will be contributing factors to a longer life for the pavers. Also, the surface of the new granite pavers has more texture than the previous pavers to provide more traction and improve pedestrian safety when wet.”
The new granite paver system is expected to not only drain more efficiently but is designed to retain the original mall’s early design.
“Laid by hand by skilled craftspeople, there will be more than 950,000 new pavers installed as part of the renovation,” Kuhn said. “The granite paver design honors the original Navajo rug and diamondback rattlesnake pattern that has been a prominent feature of the 16th Street Mall for 40 years.”
Other key features of the revitalization include:
• Moving the transit lanes to the center of the mall, eliminating the median that runs between the buses on some blocks, and creating wider pedestrian walkways and new amenity zones for leisure, commerce, entertainment and tourism.
• Honoring the mall’s iconic original design by I.M. Pei and Associates, Olin said.
• New art designed to draw people to the corridor.
The revitalized mall also will feature an improved urban tree canopy with 50 trees added to the existing 150 trees over the 13block corridor and a new curbless configuration to facilitate the movement of people and enable a variety of uses, including events and festivals, Kuhn said.
To date, crews have completed work on four blocks, with 11 more blocks in various phases of construction. The project is fund-
ed through a mix of local, state and federal funds, including voter-approved Elevate Denver bond funds and contributions from partners including the Denver Urban Renewal Authority, Colorado Department of Transportation, and Federal Transit Administration.
“The reconstructed 16th Street Mall is already on a path to becoming a more vibrant, pedestrian-friendly hub, featuring wider walkways, engaging amenities and public spaces designed for connection and community,” Kuhn said. “Its transformation will improve safety and mobility by replacing aging infrastructure while creating a showcase for business, a venue for civic engagement, a front porch for socializing, a place for relaxing and an accessible and engaging environment for both residents and visitors to experience the heart of Denver.” CEG
(All photos courtesy of denvergov.org.)
A mixer truck awaits service on the 16th Street Mall improvement project.
New transit lines are installed in the center of the mall.
Workers reconstruct an intersection.
MALL from page 1
Street Mall.
y ackast-tr can f tions and t solu our See how productivity technology our
CDE, Granite Showcase Wash Plant at Open House Event
In a state where water shortages are a common occurrence, more than 100 representatives from the materials processing industry assembled in Stansbury Park, Utah, recently to witness first-hand how a CDE engineered wash plant is efficiently managing scarce water resources.
Washing experts CDE, and Granite, one of the largest diversified construction and construction materials companies in the United States, alongside CDE’s preferred partner Goodfellow Corporation, recently showcased the 550 tons per hour (tph) solution at the plant’s Coyote Pit site.
Industry representatives from across the United States, Canada and Jamaica had the opportunity to see the wash plant in action, guided by CDE experts ready to answer any questions. The demonstration concluded with a showcase of the final materials produced by the plant for customers to see and feel.
With this solution, Granite is able to process and clean the dirty material from the area to produce five in-spec products; C33 washed concrete sand, #67 washed rock, 1 ½ in. washed rock, 3/8 in. washed chips, and ¼ in. washed chips.
Ryan O’Loan, business development manager at CDE, said it was an honor to
unveil this pioneering solution.
“We’re proud to be partnering with Granite and Goodfellow on this state-of-theart plant, and this event allowed us to demonstrate our innovative technologies to industry professionals to gain a deeper understanding of the solution’s capabilities. With the greater Salt Lake City area currently facing a severe materials shortage as resources are exhausted, this plant is vital in meeting the growing demands of the construction industry.
Industry representatives from across the United States, Canada and Jamaica had the opportunity to see the wash plant in action, guided by CDE experts ready to answer any questions.
“One of the biggest challenges we came across when designing and engineering this plant was ensuring that it could effectively and efficiently retain as much water, given the limited supply across Utah.”
The most recent study from the US Drought Monitor states that the majority of Utah, including Salt Lake County, is abnormally dry, with some areas of the state in either moderate or severe drought.
It has been reported that around 95 percent of Utah’s water supply comes from snowpacks, and reservoir storage preserves
the water for hotter months, and in periods of drought.
Earlier this year it was reported that reservoirs were at 82 percent capacity, and although this is around 18 percent higher than normal, it was important for Granite to manage and preserve as much fresh water as possible with its new CDE plant, in order to help preserve the state’s resources.
Stormy Watne, plant manager at Granite’s Coyote Pit, said, “We knew this plant would
present challenges given the complexity of water management needs, and that the deposits we’re processing being very dirty, but CDE was certainly the right partner for us. They understood our desire to recycle as much water as possible to better preserve local water resources, as well as providing technology that can process the challenging deposits, which we’re able to turn into clean in-spec material for local construction projects. We are now seeing firsthand how these challenges were at the heart of the design process.
Goodfellow Corporation’s Business Development Manager Tom Childs added, “From the moment we introduced CDE and Granite we knew this would be a meaningful and fruitful partnership. At their core, the two firms want the very best for their customers, and by collaborating, we worked together to deliver the optimal solution for Granite.
For more information, visit CDEGroup.com. (Photo courtesy of CDE.)
