The construction industry has emerged as the sector of the US economy with the greatest need for support from unmanned aerial vehicles (UAVs).  This was true well before the nation turned its attention to the enormous challenge of replacing its crumbling infrastructure. But with billions of dollars in new federal funding for this purpose now available, the trend has begun accelerating. State transportation departments are seeking to overhaul their decaying bridge and highway systems to accommodate increased vehicle traffic while enhancing road safety.  Anxious to accelerate project speed while reducing project costs, a growing number of states are also turning to drone companies to assist them.

What roles can drones play? The first and most obvious one is bridge and road inspections to properly assess the current damage and to evaluate repair needs.  Human surveyors might spend days and even weeks surveying roads with handheld cameras, sometimes perched on perilous scaffolding, risking injury or death. Traffic may have to be slowed or diverted to accommodate their work, increasing congestion and reducing the pace of commerce, increasing costs to industry and consumers alike.  Aerial drones, studies show, can greatly reduce the time and expense of these inspection efforts, allow traffic to continue at its normal rhythm, and reduce the likelihood of accidents and injuries.

But drones are far more than low-cost inspection tools. Their sophisticated 3-D imaging and sensor technology can also assist states with their aerial mapping of existing infrastructure and help forecast and model options for its expansion.  In other words, drones can become a vital project planning and monitoring tool, allowing construction managers to make key decisions that affect the project’s overall success.

A good example is the Indiana Department of Transportation (INDOT)’s planned reconstruction of The North Split interchange, just northeast of downtown Indianapolis, which merges traffic from Interstate 70 with traffic from Interstate 65. It’s the second-most trafficked interchange in the state – serving 214,000 motorists daily – but after 50 years of use, it’s reached full capacity.  As first reported in Source, the magazine of the American Society of Civil Engineers,  INDOT plans to restore 50 bridges and add 27 lane-miles of new pavement that will reduce traffic bottlenecks and accidents by eliminating “weaving,” where streams of merging vehicles are forced to cross paths with one another.  By improving road quality, the overhaul will also reduce vehicle wear and tear.

As part of its successful bid on the project, the Florida-based construction company Superior Construction requested permission from INDOT to conduct monthly aerial surveys of the entire construction site – and the state agreed. To provide the aerial footage, Superior decided to partner with an Australian-based company, Propeller Aero, which specializes in 3D drone mapping. Since November 2020,  Propeller drones have made regular biweekly flights along both sides of the interchange, at an altitude of approximately 330 ft. (In keeping with the Federal Aviation Administration prohibition of drone flights above 400 ft.).  At the conclusion of each two-hour flight, thousands of high-resolution images are uploaded into Propeller’s proprietary software platform, and then stitched together into 3D digital and terrain maps.  The software also allows for translating some of the data collected into easy-to-read charts and graphs.

The 3-D maps allow construction managers to better anticipate potential road grade issues, target the best staging areas for construction materials, analyze onsite traffic patterns and haul routes, identify physical and human safety hazards, and measure and model the overall progress of the construction effort along a number of key axes.  For a state highway infrastructure project, it’s an enormous, and some would say, unprecedented effort.

The North Split highway reconstruction is scheduled to be completed by November of this year – on budget and on schedule, a rarity for construction projects, which typically feature substantial cost overruns and project delays.  INDOT officials acknowledge that drones are a key reason for the project’s unusual success. Having slashed the usual time and cost of infrastructure surveying by as much as 80%, Satellite’s pioneering effort has practically paid for itself.

As more federal and state funding becomes available, highway infrastructure projects are certain to accelerate. According to the American Society of Civil Engineers, the decaying of the nation’s highways has left 43% in poor or mediocre condition. In addition, forty-two percent of bridges are over 50 years old and 7.5% are considered structurally inadequate. As drones continue to prove themselves in a multitude of roles relating to infrastructure development, demand for their services can only grow.