The Iowa Department of Transportation is currently testing road sensors designed to detect and warn drivers of icy road conditions, according to a KCCI Des Moines report.

The devices, called PATeye sensors, are installed in the road like center lane deflectors and begin to flash when icy conditions are present. The PATeye is designed to detect the likelihood of frost development on different surfaces, including multiple road types, rails, and sidewalks.

The sensor is triggered when the ground temperature reaches a pre-determined mark and illuminates the road to get a driver’s attention as well as illuminate any patches of black ice.

The Iowa DOT currently has two of the sensors installed in its parking lots.

In some cases, the Iowa DOT has found that the sensors were triggered too often in conditions where conditions are cold but too dry for ice to really develop. However, it remains optimistic about the benefits of the system and is working with the PATeye developer on the device’s functionality, according to the report.