Road construction causes delays, detours and confusion, but there is a light at the end of the tunnel thanks to researchers at Utah State University. A camera called Texel, created by USU engineers, is helping to reduce construction time and cut down traffic jams while saving the state millions of dollars.
In October 2007, a bridge at I-215 East and 4500 South in Salt Lake City was replaced in a single weekend, thanks, in part, to USU’s Texel camera. Using complex 3-D images that combine lidar (similar to radar, but using light in place of radio waves), digital photography and a global positioning system, the Utah Department of Transportation was able to construct a prefabricated bridge built off site to fit the existing bridge’s exact specifications.
The technique used to replace the bridge, called accelerated bridge construction (ABC), cut road closures and detours in the area from six months to a single weekend and saved $4 million in road construction costs.
“This innovation let us accomplish the work that needed to be done and not impact the driving public,” said Shana Lindsey, UDOT’s director of research and bridge operations.
The camera takes a normal digital photo of the scene in front of it, while the lidar and GPS are used at the same time to collect additional information. Once the 3-D photographic image is captured, it shows up on the screen like a normal digital photo. Unlike traditional digital photography, however, the scene is automatically embedded with distance, area and volume information. When multiple Texel photos are combined, a complete 3-D scene is formed with views from every desirable position.
“This is what lidar technology has going for it,” said Bob Pack, USU civil and environmental engineering professor and inventor of the licensed technology. “The ability to know every detail of an area before you start building saves both time and money, as there are fewer surprises.”
Pack started working on the Texel camera at the USU Center for Advanced Imaging Ladar, a former Utah Center of Excellence and current Utah Science Technology and Research (USTAR) Initiative project. The funding and notoriety gained from being a USTAR project allowed USU to license Pack's camera to a Salt Lake City-based company, InteliSum.
InteliSum worked closely with UDOT throughout the bridge replacement process.
“Prefabricated bridges offer significant advantages over onsite cast in place construction,” said Bob Vashisth, of InteliSum. “Our goal on all future UDOT ABC projects is to implement the use of the texel camera through planning, field survey, design, modeling, animation and conflict resolution before and during the actual move.”
The October bridge replacement was so successful UDOT plans to replace 13 more bridges in 2008 using the ABC method.
“The bridge replacement went exactly according to plan,” said Lindsey. “Utah’s economy is tied directly to traffic flow. We’re using taxpayer dollars and everyone benefits when we use innovation to prevent lane closures and accomplish the work faster. It was a good thing to bring this technology to Utah.”
Writer: Maren Cartwright, 435-797-1355
March 2008
