Evolving research directions toward practical bridge health monitoring with streaming data

The rapid expansion of continuous sensing has led to major growth in research on bridge structural health monitoring (SHM), with studies now addressing a wide range of problems. This review is intentionally scoped to 2022–2025 and complements rather than replaces broader foundational SHM literature. Although the existing literature is rich from many viewpoints, there is still no clear synthesis that organizes streaming-based bridge SHM studies by their core research directions. This holistic gap is important because it may remain unclear how the diverse body of recent work collectively shapes the overall purpose of bridge SHM beyond isolated techniques and focused applications. This paper aims to address this gap by reviewing 196 peer-reviewed studies published between 2022 and late 2025 on streaming time-series data for bridge monitoring. The retrieved literature is first classified by measurement strategy into direct and indirect approaches and is then organized according to the primary objectives of each study; that is, whether streaming time series data are used for damage detection, structural response analysis, estimation and prediction, data quality enhancement, digital twin coupling, or long term life-cycle monitoring and assessment. The analysis revealed various key findings, including (i) the persistent difficulty in achieving reliable damage detection under varying environmental and operational conditions due to temperature effects, traffic loading, measurement noise, and the lack of comprehensive evaluation frameworks; (ii) the fact that most existing data-driven studies mainly concentrate on anomaly detection, whereas genuine damage detection still requires further research, demanding a more in-depth understanding of the material and structural properties and backed by long-term monitoring; and (iii) the continued reliance on semi-controlled experimental validation with limited long-term field evidence.