The BL Piezo Traffic Sensor is designed by MSI for permanent or temporary installation into or onto the road surface for collection of traffic data. The unique construction of the sensor allows direct installation into the road in a flexible format so that it can conform to the profile of the road. The flat construction of the sensor gives an inherent rejection of road noise due to road bending, adjacent lanes and bow waves of approaching vehicles. The small cut in the road minimizes damage to the road, speeds up the installation and reduces the amount of grout used for installation. The BL sensor is available both as a Class I sensor for the highest level of uniformity needed for Weigh In Motion applications and as a Class II sensor which is more cost effective for counting & classifying vehicles.


  • High Output Signal for Cars, Trucks, Motorcycles & Bikes
  • Conforms to Any Road Profile and Coils to 2’ x 2’ (600mm x 600mm)
  • Sensors Can Be Mounted Permanently or Temporarily
  • Tested to 40 Million Equivalent Single Axle Loadings
  • Cable Lengths to 500’ (150m) are Waterproof for Direct Burial
  • Piezo Sensors Lengths 6’, 8’, 9’, 10’, 11’ & 12’
  • Metric Sensor Lengths 2.0, 2.5, 2.75, 3.0, 3.5, 4.0, 4.5, 5.0 and 5.5 meters
  • Installs in a 3/4” x 1” (19 x 25mm) Saw Cut in the Road Surface

International Road Dynamics also offers installation and service support for its products and systems.


  • Output Uniformity: +/- 20% for Class II (Classification) +/- 7% for Class I (Weigh-In-Motion)
  • Operating Temperature: -40° F to 160° F (-40 to 70° C)
  • Temperature Sensitivity: 0.2% per °F typical, dependent on grout used
  • Typical Output Level: A Wheel load of 400 pounds (180 kg) will produce a minimum output Signal of 250mv at 70° F (21° C) and 55mph (89kph) for proper installation
  • Passive Signal Lead In Cable: RG58C/U rated for direct burial; 3/16” (4.75mm) O.D.
  • Product Life: 40 Million ESAL’s depending on installation
  • Insulation Resistance: >500Ù
  • Installation Brackets: Included, use one per every 6” (150mm)

For successful Piezo installation, IRD recommends AS475 Grout or PU200 Piezo installation resin.