Overview
TRB’s second Strategic Highway Research Program (SHRP 2) Reliability Project L07 has released a prepublication, non-edited version of an Analysis Tool for Design Treatments to Address Nonrecurrent Congestion: Annotated Graphical User’s Guide Version 1.0. The guide is intended to assist users of the Microsoft-based Excel analysis tool. The analysis tool is designed to analyze the effects of highway geometric design treatments on nonrecurrent congestion using a reliability framework. The tool can be used to analyze a homogenous segment of a freeway (typically between successive interchanges) by allowing users to input data about site geometry, traffic demand, incident history, weather, special events, and work zones. Based on these data, the tool calculates base reliability conditions which can be used to analyze the effectiveness of treatments by providing input data of the treatment effects and cost parameters. As outputs, the tool predicts cumulative travel time index curves for each hour of the day, from which other reliability variables are computed and displayed. The tool also calculates cost-effectiveness by assigning monetary values.