Bridge Monitoring Systems with Structural Health Monitoring (SHM) and Weigh In Motion (WIM)

Bridges are critical assets that keep economies moving, yet many structures made of steel, cast iron, or prestressed concrete are aging and increasingly exposed to high traffic loads. Visual inspections remain essential but provide only momentary snapshots. Modern bridge monitoring combines Structural Health Monitoring (SHM) and Weigh In Motion (WIM) to deliver continuous, data-driven insights into structural behavior and real traffic loads, enabling operators to make informed decisions and take proactive action based on actual bridge conditions.

SHM & WIM systems provide real-time information on how bridges respond to dynamic loads, environmental factors, and long-term deterioration. This enables operators to understand load effects, detect anomalies early, and plan targeted maintenance actions based on actual bridge performance assessments.

A digital SHM sensor chain collects high-resolution data on vibration, strain, displacement, inclination, and temperature with sensors that are designed for accuracy and stability in harsh environments. These data streams provide a complete picture of how the structure behaves under varying loads and external influences.

How Weigh In Motion (WIM) captures real traffic load

Weigh In Motion measures axle loads, gross vehicle weight, speed, and vehicle class at free-flow speeds. As traffic loads and overloaded heavy vehicles are a major contributor to bridge fatigue, WIM data is essential for both assessing and protecting bridge infrastructure.

Bridge structures have limited service lifetimes – and they face growing challenges due to natural aging as well as major increases in traffic density and loading. Holistic solutions from Kistler take account of all relevant parameters to ensure effective protection for infrastructure. At the same time as monitoring the bridge’s structure, our technology measures effective traffic loading from all vehicles passing over it on a 24/7 basis. Furthermore, any vehicle violating the legal limits for gross vehicle weight, axle weight and speed can be identified and automatically penalized.

Digital SHM system from Kistler represents a new generation of bridge monitoring technology. It delivers ultra-high data accuracy and long-term stability, and it can be deployed quickly thanks to automatic configuration and a fully modular system design. The architecture is based on digital sensor clusters that synchronize measurements within microseconds and can be arranged flexibly to match any bridge. 

Digital SHM continuously measures key parameters such as vibration, strain, displacement, inclination and temperature with precision engineered sensors designed for harsh environments. Integrated edge processing enables real time detection of structural changes and, when combined with WIM, allows operators to link traffic loads directly to structural behavior. 

All data flows into a unified software platform where operators can visualize data, observe trends, set alerts and perform efficient early warning detection. This makes Digital SHM a scalable and robust solution for long-term monitoring, for the protection of critical bridges under high traffic loads.