Using visualization to sharpen the vision of public works
Bradford Henry, P.E.
Senior Associate, URS
Presenter, 2005 APWA Congress
Public works officials regularly work on projects that directly affect the entire community. Using traditional communication tools including plots, boards and spreadsheets, the extent of public works projects is sometimes not well understood, and therefore not supported, by the community.
In order to improve public understanding a new tool, visualization, is starting to be used by engineers. Using this tool, public works officials can create 3-D animated movies of engineering projects that enable constituents to see, quickly understand, and therefore support complicated engineering projects.
Following is an overview describing why visualization products are effective, what their impact has been on specific URS projects, and how the products are created.
Why is visualization effective?
Engineers have long used two-dimensional, scaled, colored layout plots mounted on boards to "explain" engineering projects. Unfortunately, the general public doesn't understand layouts. Laypersons commonly have a hard time visualizing what 2-D layout drawings of roadways, bridges, and streetscapes actually show. Layouts are complicated by the abstraction of scale, symbology and color, and therefore their meaning is frequently lost on the general public.
In contrast, seeing 3-D animated movies of engineering projects proves the old adage, "A picture is worth a thousand words."
Animations are effective because they enable the public to understand engineering projects. Humans see the world every day in 3-D and therefore they instantly understand realistic 3-D project animations. A 3-D visualization eliminates the abstraction of scale, symbology and color because it enables viewers to "see" the project exactly as if they were looking at the actual project.
What has been the impact of using visualization on specific URS projects?
URS has seen the benefit of using visualization on many projects, including three that are described below.
Project One - ROC 52: URS used visualization to show a design innovation that saved significant construction time. ROC 52 is a $240 million design-build project in Rochester, MN for the Minnesota Department of Transportation (Mn/DOT). Mn/DOT's final step in selecting a design-build contractor was a 60-minute interview. In order to "describe" its design innovation, URS created a two-minute video to illustrate flying over the project, showing on a split-screen the existing and proposed roadway at a critical interchange. By moving the new roadway and bridge 30 feet, URS was able to keep the interchange within the project right-of-way while saving Mn/DOT approximately one year of construction time.
To verbally describe the change would have required several minutes. The animation showed the modification in 15 seconds of a two-minute video, and the benefit was immediately understood. The video also showed the impact of the project on adjacent properties, the location of noise walls and the aesthetics of bridges. The value of the video has been apparent to the public involvement manager who has used it several times to explain the project and who has posted it on the project's website.
Project Two - I-494/I-35W Interchange: Visualization was used on this project to speed the public involvement process. The I-494/I-35W interchange is the second most heavily traveled route in the Twin Cities, MN metro and has to be redesigned to handle future traffic volumes. Initially to explain the new $150 million interchange to the public, Mn/DOT used traditional colored layouts. After two years of meetings, and not a lot of progress in public understanding, Mn/DOT decided to have a visualization created. The results were dramatic. Mn/DOT had public approval for the project in a matter of months.
The Mn/DOT project manager noted that the visualization improved the "quality" of questions at public meetings from vague complaints to specific project-related questions. In fact at one meeting, a mayor of a corridor city interrupted the video with the exclamation that expressed the sentiment of the audience: "Now I get it." The video showed that widening the freeway, which doubled its capacity, could be done with minimal new right-of-way.
The video had two benefits to Mn/DOT. By speeding the public involvement process, the video effectively paid for itself. In addition, in building the project's 3-D model, designers found errors in the preliminary engineering data, which therefore were corrected early, and inexpensively, in the preliminary design process.
Project Three - Midtown Greenway Bridge: Visualization was used to improve design. The Midtown Greenway Pedestrian Bridge is a $4 million, 800-foot bridge near downtown Minneapolis. URS used visualization on this project to win the work, to assist the client in selecting the most appropriate bridge type, and to help the client select final design details. Initially, to win the work, URS created an animation that consisted of a 360-degree fly-around of a 3-D model of the project that alternated between two architectural renderings of a new bridge.
Next the client, Hennepin County, MN, requested animations of three different cable-stayed bridges, including a single tower, a dual tower, and a canted tower. The visualizations showed each bridge from a variety of perspectives, including flying-above, biking through, driving under, and standing on. To select the best alternative, a team composed of the client, the public, a bridge architect, bridge designer, and a geotech expert viewed each bridge from all angles. To the team's surprise, the initially "preferred" option was not selected.
Upon selection of the preferred option, a variety of design details were added to the bridge for evaluation and final selection. These included cable attachments, railing height, retaining wall materials, pier style, landscaping, and a drainage pond.
The project site includes overhead power lines, bridge cables over a pedestrian bridge, an LRT line and a six-lane highway. Without the visualization tool, designers would have been concerned that everything would fit. With the tool, it was easily seen that everything fit into the site.
How are visualizations created?
At URS, engineering visualizations are created using actual engineering data. Initially that data is used to create a 3-D wireframe model. In the process, designers can "see" if the design elements that make up their design, including alignments, grades and cross-sections, actually fit together. With traditional design tools, this is impossible.
Next, the 3-D model is passed through software that adds realistic "materials," including concrete, asphalt, planting materials, and color to the model. Then the software is used to create a path to move through the project, in order to render images to view it as a movie. The camera path is chosen by the designer to view the project from any angle. The final result is a realistic video that enables the viewer to see the project exactly as a human would see the project after it is built without artificial scales, symbology and colors. This ability enables individual viewers to instantly understand the project and also enables all viewers to view the project with the "same" set of eyes. The URS experience is that this generally eliminates confusion and helps build project support.
In summary, URS is using visualization as an effective tool to help transportation engineers develop support for the design and construction of engineering projects that are critical to improving the public infrastructure. They are also finding out that the same tools that help the public understand engineering projects are also helping engineers design better projects, by enabling them to quickly spot and correct flaws in the design stage, and thereby lower the overall construction cost of projects.
Bradford Henry will present an educational session at the 2005 APWA Congress entitled "Using Visualization to Sharpen the Vision of Public Works." The session takes place on Sunday, September 11, at 2:00 p.m. He can be reached at (612) 373-6850 or firstname.lastname@example.org.