Image captioning for automated bridge inspection: A feasibility study

Li, M.; Liang, N.; Ma, X. and Chen, J. (2026) Image captioning for automated bridge inspection: A feasibility study. Construction Innovation, pp. 1-30. ISSN 1471-4175

Abstract

Purpose – This study investigates the application of image captioning technology in automated bridge inspection. Given the scarcity of research in this domain, this study aims to evaluate the feasibility, effectiveness and practical implications of using transformer-based models to generate natural language descriptions of bridge damage from visual data. Design/methodology/approach – A triangulated research methodology was used, comprising a systematic literature review to assess the current state of image captioning in bridge inspection; a feasibility study using an encoder–decoder architecture (EfficientNet–transformers) trained on a structural damage dataset; and an interview-based transferability study with seven industry professionals to evaluate practical adoption challenges. Findings – The systematic review identified only four relevant studies, underscoring the nascent state of research in this field. The feasibility study demonstrated promising results, with EfficientNet–transformers achieving high bilingual evaluation understudy (BLEU) scores (BLEU-1:0.944, BLEU-4:0.904) in structural damage description tasks. Finally, industry feedback highlighted potential benefits in inspection efficiency but emphasized challenges in workflow integration and model reliability. Originality/value – To the best of the authors; knowledge, this study represents one of the first comprehensive explorations of image captioning for bridge inspection, contributing both methodological and practical insights. It identifies key research gaps, including the need for domain-specific data sets and standardized evaluation frameworks, while proposing actionable directions for future AI applications in infrastructure maintenance. The findings provide a foundation for advancing automated inspection technologies toward safer and more efficient infrastructure management.

Item Type: Article
Uncontrolled Keywords: attention; bridge inspection; efficientnet; image captioning; transformer
Index terms: interview, infrastructure management, feasibility study, research methodology, integration, evaluation, inspection, workflow, dataset, methodology, effectiveness, systematic literature review, efficiency, exploration
Subjects: management, design stages, research methods, organizational analysis, infrastructure engineering, data analysis and analytics, research evaluation and metrics, data management, research design and methodology, environmental resource management, quality assurance, data collection methods, performance management
Topics: Business Strategy, Digital Applications, Quality Management, Engineering Principles, Organizational Design, Research Practice, Design Practice, Sustainability
Descriptive scope: 5 PCTEA

N.B. Descriptive scope is a count of how many of the five facets of empirical research are indicated by the words used in title, abstract and keywords. It is not intended as a judgement on the research; merely a count of the kind of word we would expect to indicate Phenomenon, Concepts, Theoretical framing, Empirical techniques, Analytical techniques. If all five are present, then a code of “5 PCTEA” will indicate this. If you feel the coding for this record is questionable, we welcome discussion around the terms we matched or the way we categorized them. The facet you would expect may not be coded, or a facet may be coded inappropriately. This can also bear on a larger question, of which facets should be treated as defining in construction management research. Please get in touch, and we will look at it. More details here