The Daily Item, Sunbury, PA

March 8, 2013

3-D images speed PennDOT project


The Daily Item

— SOUTH WILLIAMSPORT — The state Department of Transportation is using new technology in its project along Route 15 outside South Williamsport to digitally re-create the mountainside as 3-D images in a way to save time, money and ensure safety.

The Route 15 project is a two-year campaign that includes “installing center concrete median barrier, intersection improvements, embankment work, drainage improvements and resurfacing,” said Bob Johnson, of PennDOT’s Region 3 geotechnical unit.

To complete the drainage project, PennDOT’s consultant designers used a process called photogrammetry to capture digital images and transform them into a 3-D model of the mountainside, Johnson said.

“Photogrammetry has been done manually for a long time, it can now be done digitally because of the advancements in computers that can run the large amounts of data that are collected,” he said.

The model will be used to determine rock stability and the best places for drains, said Rick Mason, PennDOT’s District 3 spokesman.

The digital aspect of the job saves time and creates a safer working environment, Jones said.

“It allows for many shots on the rock face in one day that would take weeks to get manually,” he said. “Safety is a very important item. With the camera, you can stay away from the slope. Manually you are actually on the rock face taking measurements.”

The photos used to create the 3-D models were taken with regular digital cameras from multiple angles and positions and run through software, which processes the data from the photographs into geological measurements, Jones said.

On average, taking manual measurements for a similar project would take 20 to 50 days, depending on slope, Mason said. Using digital photogrammetry, the process takes one day.

PennDOT plans to continue using the software on similar projects in the region, Jones said.

“We will use it on any future rock cut projects that we can,” he said.