The Nation's bridge infrastructure depends heavily on the work of inspectors to ensure safety and performance. A high level of expertise is required to ensure that bridges meet an exacting set of standards and are safe for public use. Inspectors are therefore federally mandated to undergo comprehensive training to lead bridge inspection teams or to become program managers. This demand for high-quality training is the reason the National Highway Institute (NHI) offers training course 130055 Safety Inspection of In-Service Bridges.

Updated in 2012, the training is based on the latest edition of the Federal Highway Administration's (FHWA) Bridge Inspector's Reference Manual, which provides the most current information on the safety inspection of in-service highway bridges. Because field experience is such a valuable component of the training, NHI extended the field trip requirement to 2 bridges instead of 1, as part of the update. However, hosting agencies sometimes find it challenging to identify individual bridges with an instructive combination of deficiencies to highlight for participants. Inclement weather, travel and logistical challenges, and safety concerns also pose barriers that sometimes impede successful field trips.

To overcome these challenges, NHI now offers a 3–D, computer-based training alternative to traditional field inspection activities: virtual bridge inspection.

Developing the Training Environment

The virtual inspection exposes training participants to 30 bridge conditions and defects that reflect a wide variety of problems encountered in the field during real-world inspections.

The project team considered various forms of modeling and ultimately selected a versatile, affordable, multiplatform software program used for video game development. This solution offered the potential to create a computer-based training environment that uses high-quality graphics and is easy to navigate. The team also deemed critical two other features: that the program not require connection to the Internet or a network, since training often is conducted at remote sites with no Internet access, and that it be intuitive to use, to minimize class time spent bringing participants up to speed on how to use it.

Next, the development team created two virtual bridges: one four-span steel bridge that crosses over a divided highway and one single-span concrete bridge that spans a waterway. Each bridge has 15 checkpoints that represent defects, thereby exposing the participants to a total of 30 typical defects. The program uses an avatar -- or virtual representation of the user -- and is designed to offer a 3–D, first-person perspective.

"The software was created to help participants feel like they are physically present in the inspection setting," explains Meredith Perkins, senior instructional system designer at Sevatec, Inc., a contractor for NHI. "The environment is very realistic, with clouds and shadows, an airplane flying overhead, and a stream that moves and babbles."

Conducting Virtual Inspections

Before participants are allowed onto the virtual bridge, they must select safety gear and put it on their avatars, as well as set up the proper traffic safety features. Each participant is provided with 14 tools commonly used by bridge inspectors, including a hammer, grinder, tape measure, flashlight, under-bridge inspection truck, chain drag, and spray paint. The tools were designed to be as realistic as possible.

Participants work in teams of two and complete the same bridge inspection forms they would in the field. They can review previous reports and the Bridge Inspector's Reference Manual, and view real-life photos of the defects. Once participants have finished their inspections, the software program presents a checklist to make sure they have addressed every problem.

"When we use actual bridges, we're ‘lucky' if we can find one with five or six defects," says Douglas Blades, a bridge engineer in FHWA's Office of Bridge Technology. "You'd rarely find 15 defects on a real bridge; this way, we can train inspectors in the entire range of possible defects at one time."

To support the training, NHI created a mobile computing lab complete with 15 laptops loaded with gaming-quality graphics cards and high-resolution, 1,600- by 900-pixel screens. Thanks to this virtual inspection option, agencies now have additional flexibility when scheduling a session of NHI course 130055, which could be handy during inclement weather or when logistical issues make field trips problematic.

For course details and to schedule a session, visit NHI's Web site at www.nhi.fhwa.dot.gov.

Candice Jackson is a contractor for NHI.

Kate Sullivan is a contributing editor for Public Roads.