ABSTRACT
The HCM2010 freeway facilities methodology offers a supplemental computational engine FREEVAL, which is a macroscopic/mesoscopic tool. It enables users to implement HCM based freeway analyses quickly for both undersaturated and oversaturated conditions. Vissim is a microscopic traffic simulation tool that enables users to model real world traffic conditions with high levels of accuracy. There are few studies which assess the capability of FREEVAL to replicate oversaturated field conditions. Further, the FREEVAL tool was recently updated and coded in a new Java environment. This paper addresses a gap in the literature by contrasting the methodologies behind the two tools and by offering an explanation and discussion of their outputs in terms of density and space mean speed. The study covers three major HCM freeway segment types: basic, on-ramp, and weaving for oversaturated conditions. The assessment reveals that both tools are capable of replicating oversaturated conditions reliably after the calibration/validation process.
