Traffic data obtained in the field usually have some errors. For instance, traffic volume data on the various links of a network must be consistent and satisfy flow conservation, but this rarely occurs. A way to adjust observed values by using the concept of fuzzy optimization, so that they meet predetermined conditions, such as flow conservation equations and any consistency requirements in a network has already been proposed by other authors. This paper, however, adds two crucial improvements: One is the possibility of obtaining the best combination of adjusted values, not just the one that has a max-min membership grade but, of the combinations that meet that condition, of choosing the one whose membership grade for the rest of the adjusted values is maximum, thereby preserving data integrity as much as possible in order to attain the actual best combination. Two, the proposed method allows analysts to distinguish between reliable and non-reliable field data by assigning different ranges to each observed value when the membership function is being defined.
Samenvatting