The Correlation of Heavy Vehicle Performance Measures

Performance measures such as static roll stability, rearward amplification and load transfer ratio are a means to assess the engineering performance of heavy vehicles and to support truck size and weight policy decisions. It was expected that, for a particular vehicle configuration, there would be some degree of correlation between the various performance attributes. For example, a relatively high static roll stability may be associated with a relatively low load transfer ratio, at least within a particular vehicle configuration. In terms of developing performance measures such correlations are of great significance because (i) the number of performance attributes requiring specification may be reduced and (ii) potential conflicts between performance criteria in different attributes may be avoided. This type of analysis has not been carried out before, and requires a large database of performance numerics in order to determine relationships between each of the performance attributes. Relationships were sought for all relevant combinations of performance measures. Of the combinations investigated, several have been found to have a strong relationship with correlation coefficients of between 0.870 - 0.999 for the nineteen vehicle configurations investigated.