Louisiana Uses Drones and GIS to Modernize Infrastructure Construction

The staff at the Louisiana Department of Transportation and Development (DOTD) consider themselves curators of the state’s roadways. This requires them to be innovative in developing safe and reliable infrastructure across Louisiana’s 52,000 square miles.

As a DOTD department Location and Survey gathers a variety of data, including topographic surveys, right-of-way mapping, imagery, lidar, infrastructure condition, drainage areas, and roadway geometric data. Considering Louisiana receives 57 inches of precipitation annually, it’s one of the wettest states in the US. Collecting and analyzing drainage surface area data quickly is crucial for engineering projects and helps upper management plan effectively.

“Overall, we’re responsible for being good stewards with data for the citizens of the state of Louisiana,” said Dustin Smith, GIS specialist at DOTD.

Traditionally, many DOTs including, Louisiana's, have used airplanes to collect data using lidar, aerial imagery, or both. DOTD continues to do so for their statewide collection efforts. However, that method can be costly and time-consuming. When working with smaller areas of interest (AOI), a different collection method was needed.

Three years ago, administrators at DOTD sought a better solution to enable their staff to analyze images faster, plan for road construction projects, and assist with engineering projects throughout the state. One way to achieve their goals was to combine drones and geographic information system (GIS) technology to capture and analyze data faster.

“The smaller drones pay for themselves within the first months of us doing work,” said Jeremy Penton, GIS specialist at DOTD. Once his department acquired their first drone, he saw that Esri’s GIS offerings were an ideal pairing.
 

“We are fortunate to have all this software available to us. I was already familiar with ArcGIS Pro, so I felt like [ArcGIS] Drone2Map would be a good program for me to dive into. I was able to get an advanced license set to my [Esri] user account and started producing deliverables,” explained Penton.

Today, the department operates a fleet of six drones and employs 10 FAA Part 107 drone pilots. GIS specialists, GIS analysts, a photogrammetrist, a surveyor, an engineering tech, and two crewed aircraft pilots make up this group. The drones and GIS technology have increased staff productivity, saving countless hours of time. The introduction of a new vertical takeoff and landing drone will further enhance their capabilities, enabling staff to increase area coverage to 600–700 acres per battery set. This is essentially 10 times the areas their quadcopters can cover on a battery set.

DOTD staff use ArcGIS Survey123, a solution for capturing, visualizing, and sharing data to manage information. This enables them to keep track of who is flying which drone, who the visual observer is, what batteries are in use, different weather conditions, and more. In the past, all this information had to be collected and kept in paper logbooks.
 

Since investing in drones and GIS, DOTD can map smaller AOI datasets, including those captured using lidar. DOTD has been involved with the US Geological Survey’s (USGS) 3D Elevation Program (3DEP) for the past few years. Their role in 3DEP has empowered more senior DOTD staff to mentor and train newer members in processing UAV data.  3DEP aims to inform critical decisions that depend on high-resolution elevation data, with goals to protect life, property, and the environment, as well as assist in long-range planning for infrastructure projects. These goals align exactly with what DOTD would like to achieve on a smaller UAV collection scale. DOTD is fortunate enough to have lidar payloads for their drones. However, if they only had photo-capable drones, they still could use Drone2Map to create a photo-derived point cloud.
 

A fair amount of the drone data collection in the Location and Survey Department of DOTD focuses on drainage areas for engineering projects. Previously, staff relied on stereo imagery software to produce drainage maps. Often, each person would come up with a different result in z-values, depending on the angle they were looking from and the way they controlled the mouse. Swapping to lidar and photo-derived point clouds has reduced the potential for human error.

“We conduct volume calculations periodically across districts in the state of Louisiana,” said Smith. “[Using drones], for a typical surveying cross-section method, we have a day or two turnaround time, and not only that, but it also produces a very beautiful dataset.”

Additionally, the DOTD remote sensing team can create public relations videos. “If we’re closing a roadway or performing a project on an interchange, we go out and do videography to show where lane changes would be,” said Penton. Recently, Louisiana experienced historic levels of snowfall, where many parts of the state were covered in up to eight inches of snow. The state essentially shut down, but on day two of the weather event, “the entire UAV crew was out flying the frozen roadways. We were getting videos to show where our [road] crews were modifying and clearing roads. The public relations department used our videos in social media posts to let residents know when roads were being cleared and close to reopening,” said Penton.

Having GIS-powered online drone technology allows mobile survey crews to spend less time on the roadways themselves. Because working on busy roads is a risk for staff as well as a disruption to traffic, these innovations have made their job safer as well as more efficient. With drone technology, they can provide detailed drainage maps for watershed analysis. These maps aid in volume calculations for inventory, provide high-resolution imagery for background context, deliver valuable data for the public, and improve cost management.
 

Another application where DOTD has implemented drones and GIS is through their partnership with the Louisiana Transportation Research Center at Louisiana State University (LSU). Department personnel are working with PhD students to use videography and AI for traffic count analyses to understand and forecast patterns and risk. In addition to vehicle types and queue studies, they are coding/programming the software to do scene analysis. “When you visit different intersections throughout the city, you are getting a different scene every time,” said Penton. Having this drone footage from different areas helps the research team at LSU in their efforts.
 

“These are three-year studies in the Baton Rouge area; previously, we’ve never used this type of data to run analyses,” said Smith. In the past, staff had to collect this data in traffic in real time, which was not only time-consuming, but exposed them to roadway danger. “Anytime that we can go out with a drone, without having to interfere with the public and without having to put our team in harm’s way, it’s a reward.”