Incorporating Travel Time Reliability into the Highway Capacity Manual

This final report documents the activities performed during SHRP 2 Reliability Project L08:\nIncorporating Travel Time Reliability into the Highway Capacity Manual. It serves as a supplement\nto the proposed chapters for incorporating travel time reliability into the Highway Capacity\nManual prepared for this same project. The proposed chapters demonstrate how to apply\ntravel time reliability methods to the analysis of freeways, urban streets, and corridors. The final\nreport summarizes the work activities conducted during the course of the Phase 1 and Phase 2\nresearch by memorializing the activities, the processes, and the findings of the L08 project. In this\nway, the final report articulates the how and why of key decisions made and key activities undertaken\nduring the project so that the logic and rationale are not lost to future researchers and\npractitioners who aim to build on the work completed in this effort.\nThis report addresses the following topics:\n-\t The project’s purpose, objectives, and work tasks (Chapter 1);\n-\t The research team’s proposed definition of reliability, along with means for measuring reliability\n(Chapter 2);\n-\t A state-of-the-art and state-of-the-practice literature review (Chapter 3);\n-\t An overview of the methodologies for calculating reliability for freeways and urban streets\n(Chapter 4);\n-\t A description of the development of freeway and urban street scenario generators (Chapter 5);\n-\t Enhancements to the Highway Capacity Manual (HCM) freeway facilities methodology and\nits computational engine FREEVAL-RL (FREeway EVALuation—ReLiability), and enhancements\nto the urban streets methodology and its computational engine STREETVAL (STREET\neVALuation) (Chapter 6 and Appendices A and B);\n-\t A procedure for conducting a corridor application (Chapter 7); and\n-\t A method for future consideration to define levels of service using reliability as a service measure\nand a discussion of future research needs (Chapter 8).\n