Landscaping Albuquerque's "Big I"

The intersection of interstates 25 and 40 in Albuquerque is known locally as the "Big I." The original Big I was built in the mid-1960s at a time when the Interstate Highway System did not connect through Albuquerque, and therefore traffic routing and maintenance were of no concern. Construction of the original interchange was rather isolated from local traffic, and there was no cross-country traffic to be managed. There were a few major arterial streets affected by detours for alignment changes or the construction of grade separation structures. Only local traffic was affected in the construction area. In the 1960s, landscaping and general aesthetics were not considered a priority in highway construction projects, even within cities. Where there were concerns about soil stabilization to avoid erosion, necessary but minimal action was taken. Since the 1990s, landscaping and art have become a priority and a part of all budgets, not only in the city of Albuquerque and the state of New Mexico, but throughout the nation.

When the Big I reconstruction project went to bid in 2000, the landscaping had been removed from the scope of work in order to bring the project within available funding. Both funding and the scheduling were extremely tight. The New Mexico Department of Transportation and the city of Albuquerque agreed that the priorities were to maintain safe traffic flow during construction and complete the project in the least amount of time and under budget. Those priorities were achieved with the completed project. The city, however, disagreed with the minimal landscaping incorporated in the design under that contract and argued that the state was responsible for finding necessary funding to complete the landscaping simultaneously with the rest of the construction. Obviously, that did not happen. City leaders were disappointed by a situation that had to be faced. The result is a costly series of projects now being faced under very difficult conditions.

The city of Albuquerque and NMDOT are full partners in the landscaping effort, splitting the $10-million cost equally between them. The city, while constructing in the NMDOT right-of-way, has project management responsibility. When the projects are complete, the city will maintain the finished landscaping. NMDOT has fully reviewed all drawings to ensure compliance with state and federal standards. Landscape architects Morrow Reardon Wilkinson Miller Ltd. has the design contract and has developed the approved landscape concept. The design incorporates three distinct concepts: New Mexico foothills landscapes, high desert agricultural patterns, and sweeping forms that relate to the geometry of the interchange flyover structures. The project is divided into five bid segments, which allows for an earlier start to construction and dissipates the impact on the local landscape industry of bidding one large project. Only Segment A and Segment B had gone to bid by the end of 2007.

The Big I design is more complex than just an intersection of the two interstate highways. There are frontage roads northbound, southbound, eastbound, and westbound. In addition, several major arterials cross under the interchange. These divide the area into many parcels isolated from easy access and with significant traffic flow during most hours of the day and night. Fortunately, these frontage roads have two lanes in each direction. In places, there are three lanes to facilitate turning. These lanes are very important to provide access to the toe of slopes where work is to be performed.

Work began on the first segment of this major landscaping and beautification project in July 2007. Mountain West GolfScapes Inc. was awarded the $3-million Segment A contract. The contract includes work south from the eastbound frontage road and north from the westbound frontage road, in both areas between the northbound and southbound frontage roads. The work is from the curb elevation to the top of the embankments in those defined areas. In some areas, the embankments are two levels over the frontage roads. This translates to 40 feet to 50 vertical feet or more in places.

Traffic flow might seem to be the most difficult factor Mountain West GolfScapes has to overcome, but the real difficulty is working on slopes of 30 degrees to 45 degrees. Men and machinery must perform all the work on these slopes. Only a minimal part of the project is even close to being flat, horizontal work. The first phase in each area is to strip away the surface rock that was placed for soil stabilization under the Big I reconstruction contract. All of this rock is being reused. The stripping process is critical to minimize soil disturbance, as surface elevations must be restored. Most of this work is performed using tracked skid-steer loaders. Any excess material removed must be replaced.

Following the surface stripping, retaining walls of gabion baskets are placed on benches cut by mini-excavators. As these benches are cut into the existing slopes, temporary shoring is installed to prevent caving of the slope above the grade. Most of these walls are 6 feet high. The first level of baskets is filled from below on the slope. After the first level of gabions is in place, the higher levels are filled from above. The wire frames of the baskets are built at the contractor's staging yard, set in place and filled with stone in lifts. Earth backfill is placed behind the gabions as the work progresses. The gabion baskets have selected decorative stone placed as facing material on the visible sides. Behind these facing stones, recycled rock that was stripped from the site is used to fill the part of the baskets not seen. The facing stone includes three different materials in significantly different colors: Abo Red, Bacon and Oakwood. New Mexico Travertine supplies all of these materials.

On the slopes, different artistic patterns of surfacing rocks are employed. There is 1-inch surfacing rock in two colors — "Rio Grande Sunset" and "Buildology Brown." Also on the slopes are 2-inch to 4-inch rocks of the color "Canyon Gold." Other slope areas covered with 4-inch to 8-inch rock use two special colors: "Granite Schist" and "Sedona Red." This rock for slope surfacing is supplied by Buildology, a local firm started by Steve Hooper, well known in the Albuquerque aggregate industry.

In addition to the gabion walls, several of the slopes incorporate sweeping steel ornamental walls that bring the form of the roadway into the ground plane. These are beautiful and provide a special artistic effect. These steel structures are part of the artistic designs created by local artist Greg Reiche.

Since completion of the Big I reconstruction, there has been significant erosion. A great advantage of the landscape project is that it is permanently correcting the existing erosion problems. The established landscape will stabilize the slopes so the erosion will not reoccur. Almost all of the project areas must be restored to those finished grades after the old surfacing stone is removed. Some of the erosion has filled storm drain lines and riprap-lined channels. The Segment A contract requires Mountain West GolfScapes to remove this sediment. During the course of construction, some of the exposed slopes eroded further, requiring additional mitigation. Much of the construction work has been performed during the rainy season, requiring the contractor to pay special attention to erosion control on a daily basis.

John Mondragon, president of Mountain West GolfScapes, heads the construction team on Segment A. Korry Tilbury is the contractor's project superintendent. Buildology is the major supplier of aggregate materials. Northridge Electric is the electrical subcontractor. Action Safety provides traffic safety facilities. Walker Surveying is providing construction staking. Artistic steel fabrication is by CMY Inc. Morrow Reardon Wilkinson Miller Ltd. is the landscape architect on the project, with Greg Miller serving as lead landscape architect and Brian Verardo as project manager. Hilfiker supplies the gabions.

Barbara Taylor is the city of Albuquerque's project manager for the entire Big I landscaping program. Terry Doyle, P.E., District 3 assistant engineer, has the lead role for the New Mexico Department of Transportation's review and construction coordination.