In 2004, work began on what is currently the largest highway project in New Zealand—Auckland’s Northern Motorway Extension. The US$270 million roadway stretches for 7.5 kilometers across rugged and environmentally sensitive terrain that is home to endangered and protected flora and fauna, and is particularly susceptible to runoff.

Once complete, the highway will carry travelers through tunnels, over viaducts and bridges, and along gently winding roadways from Orewa to Puhoi. Scheduled to be completed in mid-2009, the formidable design-build project includes 3 million cubic meters of earthworks; six structures, including three viaducts; and 340-meter-long twin tunnels.

Nothing has ever been constructed in New Zealand that so intricately involved roads and tunnels through wetlands and wildlife areas. Despite these challenges, the project is not only on budget, but also currently ahead of schedule.

Because of the engineering and environmental complexities, it was imperative that the best minds from the most experienced companies join forces in a collaborative project-delivery arrangement. The result was the Northern Gateway Alliance (NGA), a high-performance project team that came together to operate as a single unit and will continue to work collaboratively until project completion.

The NGA comprises representatives from the owner and eight companies, each of which brings its own discipline—including civil engineering, design, construction, risk management, environmental engineering, and terrain expertise—to the cooperative effort. Joining Transit New Zealand (the government agency similar to a department of transportation in the United States) were Fulton Hogan, Leighton Contractors, URS New Zealand, Tonkin & Taylor, Boffa Miskell, and sub-alliance partners VSL and United Group.

Their collective vision is to "create a visual showcase of environmental and engineering excellence" with an inherent commitment to complete the project using sustainable methods and materials. New Zealand’s Land Transport Act requires that any new highway project be constructed in an environmentally friendly way—benefiting the environment and its people.

Green construction
Long before construction of the road began, members of the environmental team walked over the route and laid out grids to survey the vegetation and habitat. Their aim was to fully understand the ecosystems so that they could orchestrate a revegetation program that would appropriately revitalize the soils after completion of major earthworks. The comprehensive program includes rehabilitation of several habitat types, including degraded stream edges, natural stormwater ponds, grasslands, and saline environments.

The planting program began with hardy primary species that are able to tolerate low-nutrient soil. The first of these plants were put into the finished cut slopes in the winter of 2005.

The next phase involves planting enrichment species once the primary species are sufficiently established to provide protection. The first of the enrichment species were planted in 2008. By the time the highway is complete in 2009, the NGA will have planted hundreds of thousands of plants across the entire footprint of highway construction. It is hoped that the soil will again be able to support thousands more through natural repopulation from the surrounding areas.

Engineering challenges
On Feb. 7, 2008, the northbound Waiwera Viaduct touched land, connecting the entire 7.5-kilometer site for the first time since construction began. By spring, the southbound viaduct touched land as well, completing more than 1 kilometer of dual carriageway that sits more than 30 meters above the river estuary below. Constructing the viaduct has been one of the most complex tasks of the project, involving international input, as many as 80 full-time staff, and taking more than two years to complete. The two separate structures are each 537 meters long, and comprise 178 individual 12-meter-wide segments.

Assembly of the segments into spans as long as 76 meters was complex. Some of the segments weighed 80 tons. Initially, a weave of more than 27 kilometers of steel tendons held the segments in place. Then, more than 16,000 square meters of concrete reinforced with fly-ash was placed, along with 685 meters of subterranean piling.

Building the viaduct was just one of the major challenges the team faced. Since 2004, the NGA has moved more than 3.2 million cubic meters of material, which translates to about 10,000 cubic meters of material per day after accounting for rain delays. The movement of every bucket of earth was carefully planned months and sometimes years in advance. However, despite careful surveys and core sampling, the soil conditions that the team encountered in construction can naturally vary. Consequently, all plans had to be flexible and effectively account for the risk of varying site conditions.

In short, bringing all of these complex pieces together required not only top-notch engineering, but also world-class project management.

Project management
With an eye toward industry best practice, the NGA first defined principles, processes, and best practices for management of the entire highway program and its projects. An integral part of the NGA’s vision was to support, capture, and integrate project management processes and best practices where possible in supporting technological solutions.

The NGA defined and prioritized the following key drivers to determine whether a given solution fully supported the program: functionality, usability, efficiency, reliability, cost, and time. Because the NGA started this process early in the project development stages, cost and time were actually less important drivers.

The next step was to select the project management solution. The NGA needed a solution that provided the following:

• scale to fit all requirements and competencies;
• ability to meet functionality, usability, and efficiency expectations;
• ability to account for risk and uncertainty throughout project execution;
• maximized opportunities to gain additional efficiencies through effective communication and collaboration; and
• assurance that information was accessible and transparent to project stakeholders.

The NGA team knew early on that its requirements would inherently extend beyond the capabilities of just one solution, so it was also critical that easy interoperability with other systems be fully supported. To get the most efficient and functionally rich system, the NGA team chose Primavera.

Primavera serves as the basis for the program and project management communications center, which encompasses project planning, resource analysis, risk mitigation and management, scheduling and critical path analysis, cash flows projection, and change management. It also captures earned value, which helps the team stay on track through completion by forecasting and comparing with actual work completed to date. As a result, the NGA can verify progress made in the cost management system through its resource-loaded schedules. Team members can verify where they are to date and which scenarios or adjustments they need to adopt to complete the project successfully.

Communication among all NGA members is facilitated through use of an online dashboard, which provides real-time information tailored for each individual’s roles and needs. Designers, civil engineers, construction personnel, and environmental engineers all need to communicate as effectively and efficiently as they can, especially in a design-build project. Primavera’s web-enabled dashboards make easy communication possible.

On Auckland’s Northern Motorway Extension, the NGA seamlessly combined design-build practices, highest quality engineering, green construction principles, and project management best practices. And with a bold vision to capture and support all elements of the program within a common project management platform, the NGA enabled all team members, regardless of discipline, to work seamlessly together and maintain clear visibility of the key performance indicators throughout the program’s delivery lifecycle. To date, NGA continues to successfully deliver one of the most impressive green construction projects on time and within budget.

Richard Sappé is the industry market manager for AEC at Primavera Systems.