New Mexico’s I-25 Intersection Gets an Upgrade
Critical Reconstruction: New Mexico’s First Offset Single-Point Interchange Reaches Halfway Point
New Mexico’s first offset single-point interchange is about half-way finished at the Interstate 25 and Rio Bravo Boulevard interchange in Albuquerque.
“The designers came up with a single-point interchange but moving it off center,” says Emiliano Martinez, Project Manager for the New Mexico Department of Transportation (NMDOT). “It is controlled by different geometry. There is still a center point, but curbs and medians will control the movement. It allowed the designers to keep some through traffic moving during a turn movement.”
AUI of Albuquerque received the contract and began work in August 2017. The company’s website calls this the biggest project in AUI’s history. Crews are working seven days a week from 7 a.m. until 5 p.m., with some night work when lane closures are needed to demolish bridges, place girders or pour decks.
The road is at capacity, with poor levels of service. Heavy trucks are responsible for about 7 percent of the vehicular traffic. Additionally, numerous crashes have occurred and are associated with the congestion. The area also lacks bike and pedestrian facilities. The public has reached out asking for improvements.
The project, funded by state, federal and local dollars, will reconstruct the 1960s-era intersection. NMDOT began planning for this project in 2014, considered different interchange models, including a diverging diamond, before finalizing the design, which aims to reduce congestion and improve traffic flow.
“The designers came up with a way to move traffic with anticipation of future development near the interchange to get the capacity right,” Martinez says.
The Governor Susana Martinez identified the interchange as one of her top five, statewide transportation projects in 2015. At the groundbreaking, Governor Martinez said, “Projects like these are a great example of what we can accomplish when we work together and invest in transportation infrastructure.”
Governor Martinez hopes the new interchange will attract economic development to the area southwest of Albuquerque. A Caterpillar dealer has announced plans for a facility near the interchange, and the Mesa del Sol master planned community, with a population forecast of 80,000 residents by 2040, is being built near the intersection.
“We are trying to get a level of service for the future year, 2025, 2030, to flow through that area,” Martinez says.
The project will add one lane in each direction for 1.6 miles on I-25, replace aging bridges and entrance ramps; build a railroad crossing; upgrade the Broadway and Rio Bravo intersection; enhance storm drainage with two retention ponds; landscape; and create a 13-foot pedestrian and bicycle path. A new intelligent transportation system and traffic signals will be added. The project has been divided into six phases, with the second phase under way.
The concrete-girder bridges cross the interstate and a flood control channel.
A significant amount of earthwork has been required. About 1 million cubic yards of dirt are being moved within the project. About 500,000 cubic yards of dirt are being hauled off. The balance is being relocated to other sections of the project to fill as needed.
The job includes large cuts and retaining walls. AUI developed the shoring plans.
“We allowed the contractor to come up with a shoring plan, and that showed innovativeness,” Martinez said. “It has worked really well.”
The project included construction of “frame structures,” which will appear to be tunnels when complete. In the initial design, NMDOT anticipated the contractor would excavate the whole structure, build the walls, and brace the top slap deck with forms.
Instead the contractor built the walls, left the fill there, and backfilled to the where the deck was planned. Crews placed the deck on top of a rat slab, a thin layer of concrete. Once they are complete, the fill an rat slab will be removed.
“I thought that was smart on the contractor’s part, not having to pay for expensive forms and designing the forms,” Martinez said. “That was a good thing they did.”
Traffic Presents Challenges
AUI is keeping two lanes of I-25 open at all times.
“One of the biggest challenges has been trying to maintain traffic; there are not a lot of other options for people who live in that area,” Martinez says. “A solution was phasing. We are keeping traffic at the best-case levels during construction. The contractor and designers did a good job with that.”
At the Broadway and Rio Bravo intersection, AUI recommended reducing the number of phases from 12 to four, which the department agreed would be beneficial.
“The contractor came up with a good solution,” Martinez says. “It allowed them to get to more Portland Cement Concrete pavement pours. It sped things up.”
As part of an innovative solution to traffic problems, NMDOT has enabled the contractor to control traffic signals and signal timing in the area rather than by the DOT signal lab or the county or city.
“It’s allowed us to change the timing to adapt to some of the closures and lane movements we have done,” Martinez says. “They can make adjustments every day if they need to. It has really helped our traffic flow. That’s been a huge help to us.”
The project is scheduled for completion in 2019.
US 70 North Main, Solano, 3 Crosses and Spitz Intersection Project
AUI also has been busy working in Las Cruces on the $7.4 million U.S. 70 N Main Roadway reconstruction, lighting and signalization project, which it completed in April 2018. The intersection handles about 30,000 vehicles daily. Wilson & Co. of Albuquerque designed the project.
The work included curb and gutter, sidewalk, drainage structures, intersection improvements, utilities, permanent striping and signage, and a 20-foot earth-tone gravity wall system.
“The intersection geometry as well as the turning movement level of service were inadequate to handle the current traffic volumes,” says Ami Evans, Spokesperson for NMDOT. “The new intersection geometry allows for more efficient traffic movements and also enhances safety for motorists and pedestrians utilizing the intersection.”
The construction tool place in a busy urban intersection, which required significant coordination with government agencies, business owners and private citizens, Evans says. AUI maintained traffic and business access throughout the construction zone.
I am proud of “the hard work, dedication, coordination and project management to ensure NMDOT specification compliance by the entire project office staff,” says Evans.