Innovative WIM Sensor Layout

Blog Weigh-In-Motion

Weigh-In-Motion uses piezoelectric quartz crystal or strain gauge sensors to measure the weight of a passing vehicle. These sensors are usually installed in 2 or 3 rows perpendicular to the driving direction, so the speed of the vehicles can also be measured.


Commonly Used Layouts

Piezo polymer sensors, such as RoadTrax BL, are commonly added to the layout. They are installed approximately under a 20–40-degree angle to the weighing sensors and are used for measuring axle tracks, detecting the vehicle’s position in lane and for dual tire detection. These outputs are very important for classifying purposes and for measurement validation.

CAMEA's Innovation

CAMEA developed advanced WIM algorithms that allow installing the weighing sensors in place of the position sensors (quartz or strain gauge instead of piezopolymer). Thanks to that, less sensors in total need to be deployed which not only saves costs but facilitates cabling works as well. For instance, a configuration of 4 weighing (2 rows) + 2 piezo polymer sensors can be replaced with only 4 weighing sensors of the same or combined technology, as per the pictures below.


The innovation brings further improvements:

  • More reliable dual-tire detection,
  • More accurate and reliable position-in-lane detection,
  • More accurate and reliable axle-track measurement.

The layout also offers new functionalities:

  • Weighing with tilted (position) sensors,
  • Tire pressure measurement.

To summarize the presented innovation, a CAMEA’s SW upgrade now enables installing the WIM with the sensor layout that provides system users with better results for lower price and less works.

Effects of Direct Enforcement WIM

Lower damage to infrastructure

80 %

Significant number of violation drop in the first months

4 years

Extended road lifespan


One overloaded truck causes as much damage to the roads as almost 30,000 passenger cars. Weigh-In-Motion by CAMEA represents a solution to this by monitoring and eliminating such trucks. In addition, it contributes to traffic fluency and road safety.

More about WIM