ANALYSIS OF ALTERNATIVE SERVICE MEASURES FOR FREEWAY FACILITIES

The Year 2000 U.S. Highway Capacity Manual (HCM2000) will incorporate new procedures for the analysis of directional freeway facilities. The data base for developing this chapter provides the opportunity to analyze directional freeway facilities with undersaturated and oversaturated flow conditions, over both temporal and spatial dimensions. That chapter will also incorporate the revised HCM2000 analytical procedures for basic freeway, ramp, and weaving sections. Determining facility-based measures of effectiveness (MOE) is often a difficult proposition. A major concern in aggregating MOE for freeway facilities over time and space is how and when to combine them under both undersaturated and oversaturated conditions. Varying flow conditions may occur across segments and/or time intervals. This affects the reporting of traditional service measures of effectiveness with respect to aggregation and sensitivity. This paper reviews the technical literature on facility-based MOE, and explores alternative service measure aggregation techniques using field data, in order to overcome some of the pitfalls associated with MOE aggregation.