Chair: Peter NUTZ, Chair of PIARC TC 3.2, Austria

Most actions in winter maintenance are triggered by weather events. Weather forecasts are a very important source of Information for decision maker in winter service but they are not the only one. Together with information about road weather, road state and traffic winter service operates. New technologies in data collection, transfer and analysis enable new innovative technologies to support decision makers. Winter weather events can have very different impacts on a road network depending on the road. In addition each winter weather event is different in its own witch countless combinations of precipitation type, rate and temperatures. To compare such events and winter service operations winter indices can be used and are presented in this session. Road friction is the main value to keep up to ensure traffic safety. How winter weather affects friction and how it can be measured is part of this session.