Can drone surveying be used for infrastructure inspections? 6 ways to use it

With infrastructure aging, improving the efficiency and safety of inspection work has become a common challenge at many sites. Bridges, roads, slopes, and river structures all require regular inspections, yet many are in hard-to-reach locations, at height, or cover wide areas, and relying solely on traditional methods often requires considerable time and effort.

Drone surveying has therefore attracted attention. While drones may evoke strong associations with aerial photography and video production, today their use is expanding as a means to support inspection work by combining photogrammetry and laser measurement to capture position and shape. A major characteristic is that they do more than simply survey from above: they can detect changes in the target, enable comparative verification, standardize record-keeping, and acquire data that helps inform future repair decisions.

However, what should be borne in mind here is that drone surveying is not a panacea. In cases that require close visual inspection, that require verification of fine internal damage, or that are constrained by laws or flight conditions, it is important to appropriately combine drone surveying with conventional methods. In other words, drone surveying should not be regarded as a technology that completely replaces inspections, but as a powerful means to improve inspection accuracy and efficiency.

In this article, while answering the question of whether drone surveying can be used for infrastructure inspections, we explain six practical applications that show how it can be useful. We organize the content from a field perspective so that those considering adoption can more easily judge which sites are most likely to benefit and what to watch out for.

Table of Contents

• Can drone surveying also be used for infrastructure inspection?

• Why drone surveying is gaining attention in infrastructure inspections

• Use Case 1: Streamlining verification of elevated areas and undersides in bridge inspections

• Use case 2: Broadly assess the condition of pavements and surrounding structures during road inspections

• Use Case 3: Make it easier to detect collapse risks and deformations during slope inspections

• Use Case 4: Inspect rivers and embankments to confirm conditions across a wide area in a short time

• Use Case 5: Managing changes in large-scale structures such as dams and reservoirs

• Use Case 6: Speed up initial response for emergency inspections after disasters

• Precautions when using drone surveying for inspections

• Worksites suitable for implementing drone surveying

• Summary

Can drone surveying be used for infrastructure inspections?

To conclude, drone surveying is fully suitable for infrastructure inspections. Moreover, it increases on-site value not merely as an auxiliary imaging method but as a technology that helps with inspection tasks such as understanding current conditions, documenting and comparing them, and detecting abnormalities.

The reason drone surveying is well suited to inspections is that it can efficiently record the target from overhead, oblique, or close-up angles. Traditional inspections sometimes required scaffolding, aerial work platforms, or rope access. In contrast, drone surveying first enables a surface-level understanding of the entire object, making it easier to identify locations suspected of anomalies. Being able to grasp the object as a surface rather than as isolated points makes a significant difference in inspection planning and repair considerations.

Also, it is important to preserve captured images, point clouds, and three-dimensional models. In inspection work, not only finding anomalies on the spot but also keeping records that can be reviewed later is required. Drone surveying makes it easy to store the site’s condition as data and is well suited for checking differences from previous inspections. It has the advantage of making comparisons easy even if the person in charge changes, and it can be easily incorporated into reports.

On the other hand, when it is necessary to check crack widths extremely closely, or when sounding, palpation, or identification of internal voids is required, drone surveying alone may not be sufficient. In other words, the point of implementation is not whether drone surveying can be used for infrastructure inspection, but to determine which stages of the process it is most effective for.

Why Drone Surveying Is Gaining Attention for Infrastructure Inspections

There are three main factors behind the growing attention to drone surveying in infrastructure inspections: safety, efficiency, and record-keeping.

First and foremost, safety. The underside of bridges, steep slopes, and riverbank revetments can be dangerous for people to approach directly. If drone surveying can be used to assess conditions before forcing people into high locations, confined spaces, watersides, or areas at risk of collapse, it becomes easier to reduce on-site risk. Its value as an initial assessment is extremely high.

Next is efficiency. In infrastructure inspections, the larger the scale of the asset, the greater the effort required for travel and preparation. At sites where road lengths are long, slopes are wide, and river structures are scattered, relying solely on traditional on-foot checks takes time. Using drone surveying enables a quick aerial overview of a wide area, making it easier to narrow down the locations that should be prioritized. This improves not only the inspection itself but also the efficiency of planning.

Moreover, the importance of record-keeping should not be overlooked. Infrastructure inspections are not something that end after a single viewing; their value lies in continuously monitoring condition. If drone surveys can acquire data along the same routes and under the same conditions, it becomes easier to perform annual comparisons and to assess changes before and after disasters. Undulations and deformations that are difficult to convey with photos alone become easier to understand when preserved as three-dimensional data.

In this way, drone surveying pairs well with societal challenges such as labor shortages, measures to counter aging infrastructure, and operational standardization, and is spreading not as a mere new technology but as a practical option in real-world operations.

Use Case 1: Streamline inspection of elevated areas and undersides on bridges

One of the most typical uses of drone surveying is bridge inspection. Bridges have many areas that need to be checked—such as the superstructure, the underside, around the bearings, abutments, and piers—and they often involve high locations or span over water. Because of this, large-scale equipment and traffic restrictions are often required for each inspection.

In such bridge inspections, drone surveying demonstrates its strengths both in grasping the overall condition and in performing close-up checks. For example, by photographing not only the bridge deck but also its sides and underside, it becomes easier to identify signs of abnormalities such as dirt, delamination, water-leakage stains, and discoloration. Especially in areas that are difficult to assess by merely looking up, visibility can be enhanced by adjusting the camera angle and flight position.

Also, by creating a three-dimensional model from photographs, it becomes easier to clarify a bridge's geometry and the positional relationships of its components. A major advantage is that, rather than simply detecting anomalies, it becomes easier to share among stakeholders exactly where problems are located. Because field personnel, designers, and the client can discuss while viewing the same data, it also helps determine repair prioritization.

Furthermore, the ease of comparing data with past records is also beneficial for bridge inspections. If data can be acquired under conditions similar to the previous inspection, it becomes easier to track the progression of deterioration and to identify any new anomalies. Because bridges are often evaluated for their structural integrity through continuous monitoring rather than by drawing conclusions from a single inspection, they are well suited to drone surveying.

However, the underside of a bridge can be susceptible to radio signal conditions and wind. Consideration should also be given to surrounding traffic and obstacles. Therefore, when using drone surveying for bridge inspections, it is important to thoroughly finalize flight planning and safety management and to clearly define how much of the inspection area the drones will be responsible for.

Use Case 2: Broadly Assess Pavement and Surrounding Structures in Road Inspections

Drone surveying also proves highly effective for road inspections. Roads extend over long distances, and the items to be checked are diverse—not only the pavement surface but also shoulders, drainage ditches, retaining walls, sign foundations, and the boundaries with slopes. It is possible to inspect all of these closely by human observation, but the larger the area, the more time and personnel are required.

Using drone surveying, you can continuously capture road sections from above, making it easier to grasp overall abnormal trends. For example, as area-based information you can confirm locations where pavement settlement is suspected, shoulder collapses, areas likely suffering from poor drainage, and reduced visibility due to overgrown surrounding vegetation. It is effective as a preliminary survey before entering the site and also helps streamline routine inspections.

Another practical advantage is that photogrammetry makes it easier to compile current-condition maps of pavements and the areas around roads. It facilitates decisions necessary for road management, such as comparing conditions before and after repairs, determining whether there are traffic obstructions, and understanding relationships with the surrounding topography. Because roads are not standalone structures but are closely connected with surrounding drainage and topographical conditions, drone surveying, which can capture a broader perspective, is effective.

Furthermore, on high-traffic routes, having personnel remain on site for long periods is itself a risk. Drone surveying, which can acquire the required coverage in a short time, contributes both to shorter work times and to improved safety. Of course, attention must be paid to flight conditions and the surrounding environment, but in terms of first capturing an overall view of the target section, it is extremely well suited to road inspections.

However, when precisely evaluating fine pavement cracks and rutting, it is necessary to combine drone surveys with other investigations depending on the required resolution and observation conditions. Drone surveying for road inspection has a clear role when viewed as being strong at wide-area assessment and at identifying anomalous sections.

Use Case 3 Make It Easier to Detect Collapse Risks and Anomalies in Slope Inspections

Slope inspection is a field where drone surveying can be especially effective. Slopes often have steep gradients that make them difficult for people to approach, and securing access or footing can be challenging. Furthermore, signs of collapse may appear not only as localized deformations but also as changes in overall shape, seepage or emergence of spring water, disturbances in vegetation, or surface degradation, so a broad observational perspective is indispensable.

Using drone surveying makes it easier to inspect the entire slope from various angles. By photographing not only from above the slope but also from the front and oblique angles, cracks, loose stones, erosion, and damage to protective works can be more easily identified. If hazardous areas can be identified before people enter, the safety of the inspection plan itself is improved.

Furthermore, the value of using three-dimensional data in slope inspections is high. Slopes can be difficult to capture in terms of irregularities and deformation amounts with only planar photographs. By creating point clouds and models through drone surveying, it becomes easier to grasp terrain changes, estimate the volume of collapsed soil, and verify the effectiveness of countermeasures. Especially when the same slope is observed periodically, being able to see differences from the previous survey is a major advantage.

Additionally, slopes may require emergency inspections after heavy rainfall or earthquakes. In such situations, the primary issue is whether it is even possible to approach them. With drone surveying, you can remotely assess conditions during the initial response phase and more easily determine where attention is needed. This is a direct benefit for ensuring the safety of inspectors.

However, on slopes with many trees the ground surface can become difficult to see, and they are also more susceptible to strong winds. Therefore, drone surveying for slope inspections requires appropriately selecting imaging conditions and the equipment to be used while taking site conditions into account; this is the key to success.

Use Case 4 Inspect rivers and revetments to check large areas in a short time

Drone surveying is also highly effective for inspections of rivers and riverbank revetments. River management facilities extend over long distances and have a continuous series of features to check—revetments, levees, areas around sluice gates, slope toes, and scoured locations, among others. Relying solely on inspections on foot or by vehicle is time-consuming and increases the risk of overlooking problems.

Using drone surveying, you can quickly obtain an aerial overview of large areas along rivers. This makes it easier to comprehensively check bank deformation, signs of scour, overtopping traces, sedimentation conditions, and changes in the surrounding topography. Especially because rivers extend linearly over long distances, the ability to understand them continuously rather than in isolated sections is of great value.

It is also suited for post-flood and post-high-water inspections. Even when it is dangerous to enter the site immediately after the water has receded, being able to first verify the damage with drone surveying makes it easier to narrow down the sections that should be prioritized. It also facilitates understanding of levee surface conditions, displacement of revetment blocks, and accumulation of driftwood and sediment, improving the quality of initial response.

Furthermore, the positional relationships with the surrounding area are important in river inspections. Because multiple elements—such as roads, bridges, riverbanks, and maintenance access paths—are intertwined, drone surveying, which allows for an aerial, plan-view perspective, is well suited to organizing the situation. It also makes it easier to share an overall view of the site in reports and when explaining matters to stakeholders.

On the other hand, water surface reflections, wind, and the influence of surrounding structures can make imaging conditions difficult. Also, detailed damage assessments may require additional close-up inspection. Therefore, in inspections of rivers and revetments, positioning drone surveying as a means for overall assessment and initial extraction makes it easier to balance efficiency and accuracy.

Use Case 5: Managing changes in large-scale structures such as dams and reservoirs

Drone surveying is an easily applicable technology even for large-scale structures such as dams, reservoirs, and detention basins. These facilities cover wide areas and have elevation differences, with multiple inspection targets such as embankments, slopes, crests, and surrounding drainage facilities. Because inspections require wide-ranging mobility and multi‑faceted observation, aerial overview and three-dimensional records are useful.

The strength of drone surveying is that it can capture large-scale structures as an integrated whole. It makes it easier to grasp the overall balance, deformation trends, and relationships with surrounding terrain that are difficult to see when inspecting each part individually. For example, surface conditions of embankments, changes around drainage systems, and anomalies in surrounding slopes can be organized on the same data platform, improving the continuity of facility management.

Also, by periodically surveying the same area, it becomes easier to use the data for change management. Being able to check what has changed compared with before is highly significant for the operation and maintenance of large-scale facilities. Rather than relying solely on the subjective impressions of staff, inspection results can be accumulated as data, making it easier to enhance the objectivity of decision-making.

For facilities such as irrigation ponds, where the relationship with the surrounding ground and slopes is important, drone surveying is effective because it enables inspection that includes the surrounding areas. The value of areal data acquisition increases the more management must encompass the surrounding environment rather than treating the structure as a standalone object.

However, the higher the criticality of a facility, the more stringent the required inspection accuracy and verification procedures become. Therefore, when introducing drone surveying, it is important to clearly define and operate under a policy that specifies what will be covered by data acquisition and what will be supplemented by on-site verification and detailed investigations.

Use Case 6: Accelerate initial response in emergency inspections after disasters

Drone surveying is particularly effective for emergency inspections after disasters. After earthquakes, heavy rain, typhoons, and the like, it is necessary to rapidly confirm whether bridges, roads, slopes, river facilities, reservoirs, and other structures have been damaged. However, immediately afterward it can be dangerous to approach the site itself, and there may be traffic restrictions and risks of secondary disasters.

In such situations, initial confirmation through drone surveying can be a powerful tool. It first provides a broad understanding of the situation and can, in a short time, confirm where significant abnormalities are, whether passage is possible, and whether collapses or scour have occurred. This makes it easier to prioritize locations that require emergency response and to allocate limited personnel efficiently.

In a disaster, it's a race against time. Because it is difficult to inspect every site with the same level of detail, it is necessary to quickly gain an overview of a wide area and identify the most important locations. Drone surveying is precisely suited to this role. Because it can continuously record from the air, it is a great help in assessing the extent of damage, sharing information with stakeholders, and considering recovery plans.

Moreover, it is important to be able to document conditions after a disaster. If you preserve the situation before emergency response gets underway as data, it can be readily used later for cause analysis and recovery design. When the site is hectic, record-keeping tends to be postponed, but drone surveying has the advantage of making it easy to document and assess the situation simultaneously.

Of course, in a disaster, whether flight is possible, the weather, safety measures, and coordination with nearby activities must be carefully considered. Even so, as a means of grasping the situation in the initial response phase, drone surveying is expected to become increasingly important.

Precautions When Using Drone Surveying for Inspections

Drone surveying is useful for infrastructure inspection, but there are several points to be aware of when adopting it. If you implement it based solely on its perceived benefits, you may not achieve the expected results, so it is important to understand the limitations and conditions in advance.

First, it is important to recognize that inspections cannot always be completed with drone surveying alone. For example, confirming internal damage, conducting detailed assessments of material degradation, and checks that require physical contact may require other methods. In other words, drone surveying is not a technology that replaces all aspects of inspection; it is a technology that is strong at gaining an overall understanding, performing initial extraction, and enhancing record-keeping.

Next, there are constraints on flight conditions. On days with strong winds, in rainy weather, in areas with unstable radio environments, or in locations with many obstacles, it can be difficult to obtain stable data. Particularly careful flight planning is required around the underside of bridges and near narrow structures. While prioritizing safety, it is necessary to determine in advance what extent of operations is feasible.

Also, a data acquisition plan that matches the objective is important. If you simply fly and capture images, the data can become difficult to use later. Unless you organize in advance which parts you want to inspect, what level of accuracy and resolution is required, and whether to reacquire under the same conditions for comparison, it will be difficult to obtain results that directly support inspection work.

Additionally, organizing the collected data and establishing a system for its use are essential. In infrastructure inspections, capturing data itself is not the objective; it is important to link it to decision-making. You need to design operations that cover how images and point clouds are organized, who will review them, and how they will lead to subsequent actions. If this is left unclear, even using drone surveying can easily become a one-off effort.

Sites Suitable for Introducing Drone Surveying

So, what kinds of sites are most likely to benefit from the introduction of drone surveying? In conclusion, it is particularly well suited to locations that are difficult for people to approach, places that require managing wide areas, and situations where ongoing comparative monitoring is important.

For example, inspections at height—such as the underside and sides of bridges—hazardous locations like slopes and areas around landslides, and wide-area inspections of linear facilities such as rivers and roads are typical examples where drone surveying offers clear advantages. Conversely, if the work involves only thoroughly checking fine details within a very narrow area, other methods may be more suitable.

It is also well suited to sites where the same target is inspected regularly. In infrastructure management, it is important not only to know the current condition but also how it has changed compared with the past. If drone surveying can continuously accumulate data, it becomes easier to detect signs of change and to link that to preventive maintenance strategies.

Moreover, it is suitable for sites where accountability is high. When it is necessary to clearly convey the situation to multiple parties—such as administrators, clients, residents, and relevant agencies— aerial imagery and three-dimensional data are extremely effective. Rather than explaining inspection results with words alone, sharing them visually makes it easier to reduce misunderstandings.

The important thing is to decide not because it’s trendy, but whether it fits the challenges on site. If there are issues such as improving safety, reducing work time, standardizing records, or the need to gain an overview of a wide area, drone surveying is well worth considering.

Summary

Drone surveying is a technology that can be fully utilized for infrastructure inspections. In particular, for bridges, roads, slopes, rivers and revetments, dams and reservoirs, and post-disaster emergency inspections, it proves highly effective as a means of broadly understanding conditions and collecting information safely and efficiently.

Compared to conventional inspection methods, drone surveying has the advantages of making it easier to enhance safety for high or hazardous locations, enabling rapid inspection of wide areas, and facilitating the retention of records as data. Because inspection targets can be captured on an areal basis, a major advantage is that it facilitates extraction of anomalous areas, comparison with previous inspections, and repair decision-making.

On the other hand, it cannot completely replace detailed inspections or investigations that require physical contact. Therefore, when introducing drone surveying, it is important to clarify which processes it will be used for and what outcomes are expected. When considered in terms of roles such as overall situational awareness, initial data extraction, and standardization of records, it becomes easier to realize the benefits of its implementation.

If you want to improve the efficiency of infrastructure inspections and advance safety measures, drone surveying is a powerful option. It is particularly valuable at sites that manage wide areas or include locations that are difficult for people to approach. Viewing drone surveying not merely as aerial photography but as a practical technique that supports maintenance and management will lead to improvements at worksites going forward.