VVEXP is a prototype of a knowledge based system in winter road maintenance. VVEXP has access to a real time database that contains recordings from about six hundred field stations. One recording typically contains temperatures of air and road surface, wind speed and direction, dew point and precipitation. The recordings are presented to the local road districts. Interpretation of these recordings demands knowledge of the information system, meteorology and road maintenance. Chemical and/or mechanical utilities are used to avoid road slipperiness. If the slipperiness can be predicted the amount of chemicals used can be significantly reduced . To support decision making, a prototype of an expert system was developed. Two local road districts were assigned to the project. Field studies in the two districts and in-depth interviews with experts were accomplished in the winter of 1990/91. The knowledge of prediction of slipperiness and steps to prevent slipperiness was elicited. Systemic Grammar Network is the representation scheme used in the knowledge acquisition process to formalize the knowledge.