The Analysis Tool for Design Treatments to Address Nonrecurrent Congestion provides a Microsoft Excel-based analysis method to determine the effects of highway geometric design treatments on nonrecurrent congestion using a reliability framework. At this time the tool is supported by a prepublication version of the Annotated Graphical User’s Guide Version 1.0. Subsequent to the analysis tool's release, a Microsoft-based Excel demand generator was produced as a supplement to the analysis tool. Both tools are available in the attached zip file.
The tool can analyze a homogenous segment of a freeway (typically between interchanges) by allowing users to input data about site geometry, traffic demand, incident history, weather, special events, and work zones. Using 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. 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.
In addition to the guide and tool, there are two other resources that are a part of this project:
- Draft Design Guide for Addressing Nonreccurent Congestion that catalogs highway design treatments that can be used to reduce nonrecurrent congestion and improve the reliability of urban and rural freeways; and
- Identification and Evaluation of the Cost-Effectiveness of Highway Design Features to Reduce Nonrecurrent Congestion that focuses on geometric design treatments that can be used to reduce delays due to nonrecurrent congestion.
Analysis and Demand Generator Tools Disclaimer – The analysis tool is offered as is, without warranty or promise of support of any kind either expressed or implied. Under no circumstance will the research sponsor, National Academy of Sciences or the Transportation Research Board (collectively "TRB"), or the National Operations Center of Excellence be liable for any loss or damage caused by the installation or operation of this product. TRB and the NOCoE make no representation or warranty of any kind, expressed or implied, in fact or in law, including without limitation, the warranty of merchantability or the warranty of fitness for a particular purpose, and shall not in any case be liable for any consequential or special damages.