As more contractors are running their equipment using automated machine guidance and 3D grade controls, the demand for more civil BIM models has increased. The problem is that most design firms are still handing over paper plans.

"The disconnect is that [designers] don't always deliver 3D models," says Steven Johnson, an associate professor of civil engineering at Purdue University. "They get the standard design map that engineering firms produce, then the contractor, or someone working for the contractor, turns it into a 3D model."

On August 23, HNTB will open a lidar lab ">it is sponsoring at Purdue to boost more research in geomatics.

"We're really excited about the possibility of getting some project work for students," Johnson says.

A major limitation of lidar is that it only scans above the ground. However, recent advancements in technologies such as ground-penetrating radar (GPR) are allowing engineers to model what lies below the surface of the earth.

"There is an opportunity to put the entire site together, both belowground and aboveground," says Gary Young, senior vice president of Underground Imaging Technologies (UIT), a Latham, N.Y.-based GPR supplier. "'Underground BIM' is becoming a little bit of a buzzword."

UIT employs a trailer-mounted array of GPR sensors, which are tracked by a so-called robotic total station, rather than by GPS. The equipment can locate utilities buried 12 ft underground within 2 in. of accuracy. It then translates the data into a 3D map of the belowground infrastructure.

Last year, heavy-equipment manufacturer Caterpillar Inc. acquired UIT. Among other services, Cat hopes to use the technology to enable its 3D-equipped earthmoving machines to automatically stop digging when operators come close to striking a buried utility.

"When you think about risk management, that's what it is all about," says DiGiacobbe, who is actively researching UIT's technology.

But the problem with GPR is that, unlike mobile lidar, it can't move at highway speeds; in fact, it moves at about an acre a day. GPR also is not effective in clay soils, which make up about 50% of the country. UIT's Young says the company is testing new devices that will push those limits.

DiGiacobbe thinks that, eventually, it will be possible to drive down a road to collect above- and belowground data at the same time.

"There is a way to do it," he says. "We are going to crawl before we walk, and we are going to walk before we run."