Assessing and Addressing Deficiencies in the HCM Weaving Segment Analyses, Part II
Research Team
Nagui Rouphail, Ph.D. (NCSU)
Lily Elefteriadou, Ph.D. (UF)
Ishtiak Ahmed, Ph.D. (NCSU)
What is the current issue? This proposal describes Phase II of Project K2, titled Assessing and Addressing Deficiencies in the HCM Weaving Segment Analyses. Phase I of this project was limited to the analysis of simple, ramp weaves. It included new data collection at 15 sites in the Southeast and Western U.S., and a new speed predictive model that avoids much of the complexities in the HCM6 method. The model was found to yield more accurate speed predictions than the current HCM6 methodology. Phase II will extend the work to major weaves. As part of the original Phase I data collection, the research team had already collected volume and geometry data for 14 Type B sites which were not used in that phase. In addition, the team has access to the original NCHRP 03-75 database, which included another 10 Type B weaves. As a result, there will be no new data collection for this weaving configuration in Phase II. The team proposes to collect a limited set of new data in North Carolina (5 to 6 sites) for Type C weaving configuration, in order to cover all weaving configurations and enabling the development of new HCM material that is comprehensive across all weaving types.
What will the research produce? This work extension will address congestion mitigation by: (a) revising and updating the weave method to model operations along freeways more accurately than the current models in HCM6; (b) promoting practitioners’ trust on the macro models and specifically models included in the HCM; (c) maximizing cost-effectiveness of mobility analysis on freeways by developing an accurate macroscopic-level analysis tool; and (d) increasing the accuracy of derived analysis based on the HCM such as reliability and Active Traffic and Demand Management (ATDM) analysis.