The invention provides a traffic information display method which presents traffic information so as to quantatively indicate the reliability and superiority of traffic information. The invention also provides a traffic information providing system which clearly communicates an “unknown” section to the receiving party. The invention represents the state volume of traffic information by the state volume of each sampling point set by segmenting a target road and represents traffic information by using the state volume of traffic information and gray scale information which displays the reliability of the state volume in multiple levels. The user thus understands how reliable the traffic information is and properly evaluates the traffic information. The traffic information may be used to perform a high-accuracy path search and provide traffic information at a reasonable cost. The traffic information providing system of the invention includes traffic information providing apparatus for providing, as traffic information, the state volume of traffic information of each distance quantization unit set by segmenting a target road and mask bit information indicating that the state volume is valid or invalid, and traffic information utilization apparatus for reproducing a valid state volume by using the mask bit information. In the traffic information providing system, the receiving party clearly recognizes, based on the mask bit information, an “unknown” section enclosed by an ellipse: