Planning-Level Approach to Estimating User Cost for Freeway Work Zones

This paper presents an approach for estimating the impacts of freeway work zones in a Highway Capacity Manual (HCM) context. The freeway facilities methodology in the 2010 HCM emphasizes its applicability to the analysis of freeway work zones. In many cases, the HCM method is preferable to simulation-based analysis since it is more resource efficient, and since it can be directly calibrated to field-observed estimates of work zone capacity. However, the input requirement of the method still exceeds readily available data in planning-level work zone analyses. The method further does not include any economic performance indicators, which are critical for work zone designs in an effort to minimize the impact to the traveling public. This paper expands the HCM2010 methodology by developing a planning-level volume estimation approach using Average Annual Daily Traffic (AADT), and incorporating User-Delay Cost (UDC) and Vehicle Operating Costs (VOC) in the performance outputs. The methodological enhancements are implemented in the FREEVAL-WZ computational tool that allows for time-efficient assessment of work zone impacts in a planning context. The method is demonstrated by applying FREEVAL-WZ to computational examples that highlight the capabilities of the proposed approach. The results show that with the enhancements, analysts are able to analyze and compare different work zone scenarios in a very efficient and reliable manner.