Previous studies have shown that there are inconsistencies between the assessments of signal timing plans based on the results of optimization tools that use macroscopic simulation models and the assessments of the same plans based on microscopic simulation models. The studies show that the signal timing plans, identified to be optimal by the optimization tools, are determined to be not optimal and sometimes do not perform well according to microscopic simulation assessments. However, no attempts have been made in previous studies to determine the reasons behind these inconsistencies. This paper investigates whether adjusting the parameters of the macroscopic simulation models to correspond to the calibrated microscopic simulation model parameters can reduce the above mentioned inconsistencies. The results show that adjusting the values of platoon dispersion parameters, coded cruise speeds, and saturation flow rates in the macroscopic simulation models can have significant impacts on the performance of the signal timing plans as assessed by microscopic simulation.