Metod och system för detektering av frysning av en vätska på en väg

A system (2) and a method are provided for detecting freezing of a liquid on a road utilizing a release of latent heat from the liquid. The system comprises a sensor for measuring a road temperature, and a processor connected to the sensor and adapted to monitor temperature changes over time as measured by the sensor. The sensor comprises a measuring element arranged above and at a distance from a road surface portion (10) to continuously measure a surface temperature over the road surface portion (10). The processor is adapted to determine the release of latent heat as an increase in the surface temperature corresponding to a differential quotient between the surface temperature and time and the differential quotient exceeding a threshold value.