The Model 5422 Intelligent Road Sensor provides critical road weather measurements to aid in road maintenance decisions. The sensor is installed flush with the road surface for direct measurements of road surface temperature, water film height, freeze point temperature, chemical concentration, road condition (Dry, Damp, Wet, Ice or snow, damp to frost). Optionally, up to two subsurface sensors can be connected directly to the sensor housing reducing extra wiring.

Surface temperature is measured just below the surface of the sensor with an accurate NTC type sensor. Water film thickness is measured using a radar principal and can detect the depth of the water layer up to 4 mm. Freeze point and ice percentage is determined by analyzing the conductivity of a chemical solution. The two part housing design is constructed of aluminum and acetal copolymer materials which have thermal characteristics similar to common pavement materials.

The road surface sensor is typically connected to a Remote Processing Unit or controller in a Road Weather Information System (RWIS) with its open protocol RS-485 communications.