New technology helps construction workers survey landscape

MILWAUKEE -- Strange markings and slow vehicles have popped up on area roadways, and while resulting traffic may be a hassle, officials say the alternative would mean more delays.

The new markings are half-outlined black squares. They're not a new form of speed detection or some unknown traffic marker, but rather for measurement purposes with the "LIDAR System."

LIDAR, or Light, Detection and Ranging, is a relatively new way to map out the landscape. Wisconsin's Department of Transportation is using the process to aid in roadway design and construction projects. However, the squares are only part of the equation. Trucks equipped with the actual LIDAR technology are used to perform the survey of the land.

"It's a way of capturing all the existing topographic information that's out there on the freeway," Steve Hoff with the Wisconsin DOT said.

Two sensors mounted on the truck continually shoot pulses of light in all directions. The light then bounces off surrounding objects and returns to the sensors.

"It records the amount of time it takes, and can create a three-dimensional picture of a surface," Jason Krueger with Ayres Associates said.

Unfortunately, the truck cannot quite match the speed of traffic, ultimately slowing everyone else down. However, the now old-fashioned alternative would likely frustrate drivers more.

"Using this kind of equipment we can avoid putting a lot of personnel out on a traveled way and having to close lanes," Krueger said.

"Driving something like this is pretty quick. They can do a 14-mile stretch in probably a week or so, whereas if you were to do that with a two-man survey crew that could take several weeks," Hoff said.

One other big benefit -- no workers along the roadways means no risk of those workers getting hit.

The I-43 corridor isn't the only location where the new technology is being used. It was also used in the Zoo Interchange and both ways on I-94 around Miller Park.