Two i.ce warning systems were installed on the Interstate hi.ghway system in the Oklahoma City area. A Boschtmg Canpany, Inc. Ice Early Warning System was installed on three elevated structures or bridges. A Surface Systems Inc. SCAN System was installed on one of the structures. The systems were evaluated for two winter seasons. The primary objective of the evaluation was to determine the data accuracy and reliability and the durability of the equipment in the operational environment. The Boschung system was used by a field maintenance division to augment their weather surveillance nethods and as an aid to gain knowledge on icing conditions. The relatively few icing events which occurred during the evaluation period limited the arrount of data available for analysts and equipment evaluation. The basic sensor responses to weather and surface conditions appeared to be accurate and reliable . The logic derived early warning alarms or surface condition status alerts were not as easy to interpret or verify due to the lack of repeatable weather conditions. The systems denxmstrated the potential to be of value as a deci.si.on support tool. Further operational experience and evaluati.on by the maintenance supervisors responsi.ble for deicing operati.ons would be beneficial in order to better assess the feasibility of futrure s:rstem expansion.