National Highways Tests Driver Reactions as Low-Flying Road Monitoring Drones Move Closer to Reality

Drones could soon become a familiar sight above Britain's motorways after National Highways completed a pioneering study designed to assess whether the technology could distract drivers.

The research forms part of plans to deploy a new generation of low-flying drones capable of carrying out detailed inspections of roads, bridges and other highway assets without the need for traffic management or engineers working close to live traffic.

While drones have already been used by National Highways for infrastructure inspections since 2020, future operations could see much smaller aircraft flying significantly closer to the road network than current regulations typically allow.

To understand how motorists might react, National Highways and engineering consultancy Arup commissioned a series of virtual reality driving simulations involving more than 120 motorists and 19 HGV drivers.

Participants were placed in highly realistic motorway driving environments where drones were operating nearby, without initially being told that the study was focused on drone activity. Researchers then monitored driving behaviour alongside physiological responses such as heart rate, eye movement and pupil dilation to determine whether the aircraft affected concentration or vehicle control.

The results suggest that while many participants noticed the drones, far fewer considered them a hazard or believed they negatively affected their driving performance.

The findings could pave the way for a wider rollout of low-altitude drone operations across England's strategic road network as early as 2027.

According to National Highways, the smaller drones would typically operate between 10 and 20 metres above the carriageway, significantly lower than many existing drone inspections which often take place at around 50 metres.

The lower operating height would allow engineers to capture more detailed imagery of road surfaces, structures and assets while also reducing operational costs. Officials estimate the smaller drones could be around ten times cheaper to deploy than larger alternatives currently used for inspections.

The technology has the potential to transform how highway authorities monitor and maintain infrastructure, providing faster access to condition data while reducing the need for lane closures and site visits.

Ewan Murdoch, Senior Consultant at Arup, believes the work is attracting international attention as road authorities look for safer and more efficient methods of asset inspection.

"We've had some interest from colleagues in Australia and the United States who are looking at similar opportunities," he said.

"This methodology is quite novel and we're seeing strong interest globally in how it could be applied."

National Highways says the research represents one of the first large-scale attempts to scientifically assess how drivers respond to low-flying drones in a road environment.

Callum Brown, Senior Adviser on Airspace Standards at National Highways, described the project as a significant step forward in integrating drone technology into highway operations.

"We're at the cutting edge of this work and have been building towards it for around six years," he said.

He added that the technology could become one of the safest and most efficient ways of surveying road infrastructure in the future.

The study also highlights how rapidly drone technology is becoming embedded within infrastructure management. Across the transport sector, drones are increasingly being used for bridge inspections, asset monitoring, emergency response and construction projects, reducing costs while improving worker safety.

For National Highways, the next challenge will be translating the findings into operational approvals that allow drones to be deployed more routinely across the strategic road network.

If successful, motorists could soon find themselves sharing the skies above Britain's motorways with a fleet of intelligent inspection drones helping to identify defects, monitor assets and improve the efficiency of highway maintenance operations.

The research suggests that for most drivers, they may barely notice them at all.