While it's hard to find consensus in Washington, D.C., on most topics these days, almost everyone agrees that our nation's infrastructure is in critical need of extensive repair and expansion. On July 6, 2012, President Obama signed into law the groundbreaking Moving Ahead for Progress in the 21st Century Act (MAP-21), funding surface transportation programs for fiscal years 2013 and 2014. What makes this transportation bill different from past bills is the recognition of technology and process change as a necessary means to achieve national transportation goals. As such, the Act has the potential to fundamentally transform how our country designs and builds infrastructure.
In MAP-21, Congress declares that "it is in the national interest to promote the use of 'innovative technologies and practices'" to expedite projects, reduce cost, enhance safety, and protect the environment. Even before this assertion by Congress, government agencies and private-sector firms around the country had started to understand that moving from outdated highway design and construction methods – many of which had not changed in half a century or more – to smarter, model-based processes such as Building Information Modeling (BIM), results in higher-quality solutions, delivered faster and at lower cost. But now, they recognize that incremental change and simple advances of yesterday's technologies will not suffice.
Realizing the full power of model-based design
Consider an example in the State of Washington. The Salmon Creek Interchange project was a joint effort between the Washington State Department of Transportation (WSDOT) and the Clark County Public Works Department. The project includes construction of a new interchange between Interstates 5 and 205 in southwest Washington, as well as other improvements to ramps and local roads. Clark County was responsible for the design and construction of all of the elements needed on both sides of the I-5 and I-205 freeways to facilitate the new interchange under design by WSDOT. Clark County faced strict deadlines as construction funds were tied to specific construction seasons and the county's work had to be finished before WSDOT could start its construction. In addition, late in the design process WSDOT determined that because of groundwater issues the interchange must go over the freeway instead of the original tunnel strategy – requiring the county to completely redesign the freeway frontages.
Clark County used a model-based approach to help reduce its project design and redesign times and meet its deadlines. The team also created a 3D infrastructure model of all the pipe networks for the new drainage system as well as the complex web of existing utilities (including gas, storm sewer, water, sanitary, and fiber optic). The team used this model to help keep all the utilities, the proposed drainage system, the corridor designs, and associated documentation in-sync with each other at all times to minimize design conflicts and improve quality. This model-based workflow also helped construction personnel better visualize the county's design to help expedite construction.
A component of MAP-21 requires the Secretary of Transportation to encourage the use of advanced modeling technologies, including 3D modeling tools such as those utilized in Clark County, that can "accelerate and improve the environmental review process; increase effective public participation; enhance the detail and accuracy of project designs; increase safety; accelerate construction and reduce construction costs; or otherwise expedite project delivery."
The Everyday Counts Initiative (www.fhwa.gov/everydaycounts), which is part of MAP-21, encourages the use of technologies that take projects from conception to completion quicker. According to Sundt Construction, BIM plays a big role in that.
Sundt Construction and its joint venture partner Slayden Construction are the construction manager/general contractor on the Sellwood Bridge reconstruction project in Portland, Ore. During the proposal phase, the Slayden/Sundt joint venture used 3D modeling to develop a faster, safer, and less expensive method for reconstructing the bridge. They recommended constructing a detour bridge by installing temporary piers and approach spans next to the existing bridge and sliding the original bridge's steel deck truss onto those temporary structures. The detour bridge would eliminate the cost of steel for two extra ribs running down the middle of the bridge – redundant structural features needed if each half of the bridge was freestanding during construction. It would also free up the existing alignment for more efficient construction and immediately improve safety by offloading traffic from the cracked concrete piers supporting the existing bridge.
Because site conditions around the bridge were extremely tight, with some adjacent buildings literally built around the foundation columns of the old bridge, the team needed to demonstrate clearly the feasibility of constructing the detour bridge.
For the precise preconstruction planning and visualization that was needed, Slayden/Sundt created 3D models of the existing bridge and site, the detour bridge, and the new bridge. These virtual models were used to explore and evaluate construction alternatives, and ultimately resulted in the adoption of an innovative construction approach that will shorten the project schedule by approximately one year and reduce costs by $5 million to $10 million according to www.SellwoodBridge.org
On the technology side, new offerings, such as Project Mercury from Autodesk, address the urgent need to simplify, speed up, and reduce costs across the project lifecycle. Project Mercury enables transportation workflows unlike traditional 3D CAD-based solutions or solutions that focus on 2D layout and drafting alone. Project Mercury enables engineers to design in 3D from the start, laying out geometry in the context of the surrounding environment and regulatory constraints. With the ability to easily incorporate existing conditions and other design elements and then quickly visualize the project in 3D, even non-technical stakeholders can make better-informed decisions more quickly. Designs are optimized earlier in the process when changes are less costly and time-consuming to make and then design intent is more accurately conveyed, without loss of data fidelity, from preliminary to detailed design and on to construction.
Users can take advantage of a cloud-based environment which enables the engineering team to work in a collaborative ecosystem where accurate feedback and updates from stakeholders can be captured via web and mobile devices. With 3D model publishing and sharing capabilities, even large-scale infrastructure projects can be shared easily and accurately to communicate to regulatory agencies or the public at large. Accurate, understandable communication is the key to accelerate and improve the environmental review process, increasing effective public participation and enhancing the detail and accuracy of project designs as MAP-21 outlines.
As the Sellwood Bridge and Salmon Creek Interchange projects illustrate, the vision of MAP-21 is achievable. MAP-21 ultimately marks the end of the era when 2D drawings are adequate and decades-old project delivery procedures continue without radical reform. It signals confidence that the best of America – people and technology – can transform our transportation processes to achieve new efficiencies that save taxpayer dollars, accelerate progress, and protect the environment.
Karen Weiss, P.E., senior industry marketing manager for Infrastructure for Autodesk, has worldwide responsibility for go-to-market strategic realization for the civil infrastructure industry sub-segments. Weiss spent 19 years working in the transportation industry, holding engineering positions in both the public and private sectors. For the last four years she has focused on developing industry-focused marketing programs for infrastructure including roads and highways, rail, land, and water.