Superloads, or "super heavy" vehicles are a growing occurrence on North Carolina bridges and highways. Due to their non-typical weights and geometries, as well as the difficulties of verifying such values, additional information is needed to prevent damage to bridge superstructures and highway pavements. The NCDOT Problem Statement 2403 addresses the need for basic data and analysis on the relationship between estimated axle load distributions provided by truck operators and actual axle load distributions, as well as the impacts of superloads on North Carolina bridges and highways.
The research produced the following results: (1) Weight distributions of superloads acquired through field weighs and permits from project partners and other DOTs; (2) Estimates of pavement damage from superloads in terms of ESALs and equivalent number of 80 kip trucks. (3) Recommendations for PMU superload permit application analysis (4) Estimates of superloads' distribution of demands on bridge superstructures for selected superload types; (5) Recommendations regarding the current NCDOT permitting process for superloads crossing bridges; (6) An updated version of the NCDOT program, PERM6 capable of analyzing vehicles with up to 50 axles.
