In one exemplary embodiment of the invention, a method of regenerating an exhaust gas particulate filter in a vehicle having an internal combustion engine is provided. The method includes determining a soot accumulation in the particulate filter, determining a soot humidity and temperature correction factor, and adjusting, using the soot humidity and temperature correction factor, the soot accumulation to determine a corrected soot accumulation in the particulate filter. The method further includes performing a regeneration of the particulate filter when at least one of the following occurs: the corrected soot accumulation reaches a predetermined threshold, and the corrected soot accumulation indicates a contorted soot mass to flow resistance relationship.