Smart Bridge Safety System

Abstract

The proposed Smart Bridge Safety System is an Arduino Uno–based embedded monitoring and alert system designed to improve bridge safety by detecting abnormal structural movement or load conditions. The system uses a flex sensor connected through the analog pin to continuously monitor the bending or strain developed on the bridge structure. The sensor readings are processed in real time by the Arduino Uno microcontroller, which acts as the central controlling unit of the project. The main objective of this system is to provide an early warning mechanism for possible bridge damage, excessive load, or unsafe structural conditions. In this project, a BF350 strain/flex sensor is used to measure deformation or vibration on the bridge surface. The analog values obtained from the sensor are read through the Arduino’s ADC pin. To ensure accurate readings, calibration constants such as gauge factor and excitation voltage are defined in the program. At the startup stage, the system automatically performs zero calibration (auto tare) by reading the initial sensor value when no load is applied. This value is stored as the reference offset for future comparison. The sensor values are continuously displayed on the serial monitor and LCD display for real-time observation. A 16×2 I2C LCD module is integrated into the system to provide user-friendly monitoring. The LCD displays messages such as “Smart Bridge” along with live sensor values. This allows the operator to easily monitor the condition of the bridge without requiring additional software tools. The use of the I2C interface reduces wiring complexity and improves system efficiency representing a warning or bridge closing action. Simultaneously, the buzzer is activated to provide an audible alert to nearby users and authorities.

Introduction

The text describes a Smart Bridge Safety System developed using Arduino and IoT-based sensors to monitor bridge health and prevent accidents caused by strain, bending, or overload.

The system uses a BF350 flex sensor to continuously measure bridge deformation. The Arduino Uno processes this data, and when the sensor value exceeds a set threshold, the system triggers safety actions: a servo motor rotates to block the bridge, and a buzzer activates an alarm to warn users. An LCD display shows real-time sensor readings and system status, switching between normal and danger conditions.

The main objectives of the system are to:

• Monitor bridge strain and vibrations
• Detect abnormal structural movement
• Display real-time data on LCD
• Control bridge access using a servo motor
• Provide immediate warning through a buzzer
• Prevent accidents through early detection

The literature review highlights that structural health monitoring has evolved using technologies such as wireless sensor networks, fiber optic sensors, piezoelectric systems, and low-cost Arduino-based solutions. These studies emphasize improved accuracy, real-time monitoring, and cost-effective safety systems for infrastructure.

Conclusion

The above Arduino program represents a Smart Bridge Monitoring System using a flex sensor, servo motor, buzzer, and LCD display. The flex sensor continuously measures the bridge condition by detecting strain or bending values. These sensor readings are displayed on the LCD screen and also monitored through the Serial Monitor. When the sensor value crosses the threshold value of 523, the servo motor rotates to 90 degrees and the buzzer activates, indicating a warning condition such as excessive load or possible bridge damage. If the sensor value remains below the threshold, the servo stays at 0 degrees and the buzzer remains off, showing that the bridge is safe. Therefore, this system helps in real-time monitoring of bridge safety and provides an early warning mechanism to prevent accidents and structural failures. readily.

References

[1] E. OBrien, M. A. Khan, D. P. McCrum, and A. Alessandro Sabato Laboratorio di Tecnica del Controllo Ambientale Dipartimento di Ingegneria Meccanica, Energetica e [2] Gestionale (DIMEG) - University of Calabria developed “Pedestrian bridge vibration monitoring using a wireless MEMS accelerometer board” 2015 IEEE 19th International Conference on Computer Supported Cooperative Work inDesign (CSCWD), 2015. [3] Amro Al-Radaideh, A. R. Al-Ali, Salwa Bheiry, Sameer Alawnah [3] developed an “A Wireless Sensor Network Monitoring System for Highway Bridges” 1st International Conference on Electrical and Information Technologies ICEIT?2015. [4] Ren-Guey Lee1, Kuei-Chien Chen [4] developed an “A Backup Routing with Wireless Sensor Network for Bridge Monitoring System” 4th Annual Communication Networks and Services Research Conference (CNSR?06),2006. [5] Anshu Adwani1, Kirti H. Madan2, Rohit Hande3 “Smart Highways Systems for Future Cities” International Journal of Innovative Research in Computer and Communication Engineering Vol. 3, Issue 7, July 2015. [6] Yan Yu1, Hang Liu1, Dongsheng Li2, Xingquan Mao1, Jinping Ou2 “BRIDGE deflection measurement using wireless mems inclination sensor systems” international journal on smart sensing and intelligent systems vol. 6, no. 1, february 2013. [7] Matthew J. Whelan, Michael V. Gangone, Kerop D. Janoyan, Ratneshwar Jha “Real-Time Wireless Vibration Monitoring for [8] Operational Modal Analysis of an Integral Abutment Highway BridgeŽnidari?,“Using Statistical Analysis of an Acceleration-Based Weigh-In-Motion Systemfor Damage Detection,” Applied Sciences, [9] A. Malekjafarian, C.-W. Kim, E. J. OBrien, L. J. Prendergast, P. C. Fitzgerald, and S. Nakajima, “Experimental Demonstration of a Mode Shape-Based Scour-Monitoring Method for Multispan Bridges with Shallow Foundations,” Journal of Bridge Engineering, [10] M. A. Khan, D. P. McCrum, L. J. Prendergast, E. J. OBrien, P. C. Fitzgerald, and C.-W. Kim, “Laboratory investigation of a bridge scour monitoring method using decentralized modal analysis,” Struct Health Monit, [11] B. Bachinilla, A. Evangelista, M. Siddhpura, A. N. Haddad, and B. B. F. da Costa, “High-Speed Railway Bridge and Pile Foundation: A Review,” Infrastructures (Basel),

Copyright

Copyright © 2026 Basweshwar M Bansode, Harshal Atugade, Binesh Jaiswar, Sohan Salunke, Moosa Shaikh. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.