Load equivalency factors (lefs) versus axle-load regression equations are reported for single-, tandem-, and tridem-axle groups. These functions have been developed from truck loading test data collected at nine sites across canada in 1985 by the canroad transportation research corporation. While the load on the axle groups dominated the regression equations, pavement temperature, axle spacing, and vehicle velocity were found to be statistically significant for the tandem-axle groups at a number of the sites. Regression analysis of the pooled tandem data showed that load and axle spacing were significant. Analysis of the pooled tridem-axle group data showed that load, axle spacing, structural number, and vehicle speed were significant. The load equivalency functions are compared with the aashto functions and the differences highlighted. This paper appears in transportation research record no. 1196, Pavement evaluation and rehabilitation.
Abstract