Design and verification of a non-intrusive portable FBG sensing belt for vehicle detection and speed measurement on road surfaces

This research article presents the design, development, and field validation of an innovative portable fiber Bragg grating (FBG) based optical sensor for vehicle detection and speed measurement in road traffic. The proposed system offers a non-invasive installation method that avoids pavement disruption and enables rapid deployment in urban environments. The sensor was designed with a reinforced aluminum core and polymer encapsulation to ensure mechanical robustness and effective strain transfer. Finite element modeling and mechanical testing were employed to optimize sensor geometry and placement. Experimental testing demonstrated reliable performance under both laboratory and real traffic conditions, achieving a detection accuracy of 99.92%, and a maximum speed deviation of ± 1.5 km/h compared to a reference system. The observed distinct signal amplitudes and waveform shapes for various vehicle types (motorcycle, bus, truck) highlight the significant potential of this sensing belt for advanced vehicle classification, which will be a focus of our future work. Overall, the proposed non-intrusive and portable sensing belt is well suited for rapid deployment in intelligent transportation systems and municipal traffic monitoring.