Traditional bridge inspection practices rely heavily on visual assessment by trained inspectors, which can be time-consuming, subjective, and constrained by accessibility, safety concerns, and increasing infrastructure aging. In recent years, artificial intelligence (AI), particularly computer vision–based approaches combined with unmanned aerial vehicles (UAVs), has emerged as a promising tool to support and enhance bridge inspection activities. This paper presents a comprehensive review of recent advances in AI-enabled bridge inspection, focusing on image-based defect detection, classification, and condition assessment using deep learning techniques.
A structured review of peer-reviewed literature published between 2015 and 2024 was conducted across major scientific databases, identifying representative studies that apply convolutional neural networks, segmentation models, and hybrid vision architectures to detect common bridge defects such as cracks, spalling, corrosion, and surface deterioration. The reviewed studies demonstrate that AI-assisted methods can achieve reliable defect recognition, particularly under controlled and semi-controlled inspection conditions, and offer significant potential to improve inspection efficiency, documentation quality, and inspector safety when integrated with UAV-based data collection.
Beyond algorithmic performance, this review critically examines practical implementation challenges, including data quality and labelling requirements, model generalization across different bridge types and environmental conditions, explainability of AI predictions, and integration with existing inspection workflows and regulatory frameworks. To address these challenges, a practice-oriented hybrid inspection framework is proposed, emphasizing human-in-the-loop decision-making where AI systems support, rather than replace, professional judgment.
The findings of this review highlight both the opportunities and limitations of AI-enabled bridge inspection technologies and provide guidance for engineers, infrastructure owners, and agencies seeking to adopt these tools in real-world inspection and maintenance programs. The paper concludes by outlining future research directions aimed at improving robustness, field validation, and practical deployment of AI-assisted inspection systems within modern bridge management and infrastructure maintenance programs.
Introduction
Bridge inspection is critical for maintaining the safety and reliability of transportation infrastructure. Traditional visual inspections are time-consuming, subjective, and dependent on inspector expertise. Recent advancements in Artificial Intelligence (AI), Computer Vision (CV), and Unmanned Aerial Vehicles (UAVs) have improved defect detection, classification, and monitoring by automating inspections, increasing accuracy, and reducing risks to inspectors.
A systematic review of 65 studies (2015–2024) examined the use of AI-based technologies for bridge inspection. Deep learning models such as Convolutional Neural Networks (CNNs) have demonstrated high effectiveness in detecting cracks, corrosion, spalling, and other structural defects. Segmentation techniques provide precise damage localization, while transfer learning and data augmentation improve model performance when labeled datasets are limited. Edge computing and lightweight AI models further support real-time inspection using UAV platforms.
Several pilot projects conducted by transportation agencies and researchers have shown that AI-assisted inspections can enhance consistency, efficiency, and access to difficult-to-reach bridge components. However, widespread implementation remains limited due to challenges such as insufficient annotated datasets, environmental variability, model reliability, lack of interpretability, regulatory concerns, and integration with existing bridge management systems.
To address these issues, the study proposes a hybrid AI–human inspection framework consisting of five stages: data acquisition using UAVs, AI-based defect detection, expert validation by inspectors, model refinement through feedback, and regulatory collaboration for certification. This approach maintains professional accountability while leveraging AI’s efficiency.
Future research should focus on multi-sensor data fusion (combining visual, LiDAR, thermal, and acoustic data), edge-cloud integration, development of standardized datasets, AI governance and ethics, and predictive maintenance systems. Economic considerations such as equipment costs, training, and infrastructure investment must also be evaluated to ensure sustainable adoption. Overall, AI-assisted bridge inspection has significant potential to improve infrastructure monitoring while supporting safer and more efficient asset management practices.
Conclusion
Artificial intelligence has emerged as a promising technology for transforming traditional bridge inspection practices. The integration of computer vision techniques, deep learning algorithms, and UAV-based data acquisition has significantly enhanced the ability to detect structural defects such as cracks, corrosion, and concrete spalling. These technologies offer the potential to reduce inspection time, improve detection accuracy, and enhance the safety of inspection personnel by minimizing the need for manual access to hazardous bridge components.
The literature reviewed in this study demonstrates that deep learning models, particularly convolutional neural networks, have achieved high accuracy in automated defect detection from bridge images. When combined with UAV platforms, these systems enable efficient large-scale infrastructure monitoring and provide high-resolution data for structural condition assessment. Such advancements can support more proactive maintenance strategies and contribute to improved asset management for transportation agencies.
However, despite the progress made in recent years, several challenges remain before AI-based bridge inspection systems can be fully adopted in practical applications. Key limitations include the lack of standardized datasets, difficulties in detecting small or complex defects under varying environmental conditions, and challenges related to model generalization across different bridge types and materials. Additionally, integrating AI technologies into existing inspection standards and regulatory frameworks remains an important consideration for infrastructure authorities.
Future research should focus on developing more robust deep learning models, expanding large-scale labeled datasets for structural defects, and integrating multiple sensing technologies such as LiDAR and digital twin systems. The development of real-time monitoring platforms and autonomous inspection systems also represents a promising direction for advancing infrastructure health monitoring.
Overall, AI-enabled bridge inspection systems have the potential to revolutionize infrastructure monitoring by providing faster, safer, and more accurate methods for structural assessment. Continued research and collaboration between civil engineers, computer scientists, and infrastructure agencies will be essential to fully realize the benefits of these emerging technologies in maintaining the safety and reliability of bridge networks worldwide
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