The pedestrian slippery index model is a special version of the road weather model that, instead of road weather, determines the condition existing on pavements from the viewpoint of pedestrians. It differs from the road weather model mainly with respect to the description of wear of ice, snow, etc. and in the interpretation of weather details. In addition, the determination of the forecast initial state uses data from a longer observation simulation period.
The input data used for the weather variables are the same as for the road weather model, namely atmospheric temperature, wind and humidity as well as solar radiation, thermal radiation from clouds, and precipitation. The model has been developed in collaboration with the Institute of Occupational Health using data from measurements performed with a walking robot wearing a variety of shoe models in real pedestrian walking conditions.
The model produces similar surface condition interpretations as the road weather model, but the index calculated on the basis of them is different and uses criteria proper for the estimation of slipperiness when walking on pavements. The reason for differing criteria is that hazardous conditions for motorists on roads and pedestrians on pavements arise from different reasons and in different situations.
The slippery index can have the following values:
The results of the model are used to assist meteorologists to issue warnings to pedestrians when necessary. In addition to operational forecasting, the model is used in research.