A Highway Capacity Planning Application and Development of Default Values in North Carolina

The North Carolina Level of Service (NCLOS) methodology provides a planning-level assessment of transportation facilities through a generally faithful implementation of the 2010 Highway Capacity Manual (HCM) to derive service volume estimates and performance expectations, with a few minor deviations from the HCM 2010. Implemented in the NCLOS software tool, the method gives a visual representation of traffic volume plotted against the various measures of effectiveness for each facility type. The graphical output shows the feasible performance range from the best to the worst case scenarios for each facility type in North Carolina based on different default values, as well as an average default scenario. The user-defined subject facility is evaluated within that range of values to give the user a direct assessment of the performance. The user can conduct a sensitivity analysis of various scenarios by altering the input values to represent possible design considerations for a particular highway. The tool also enables the user to produce a numerical report detailing the results of the analysis, as well as the ability to export the calculated capacity to transportation planning software and travel demand models. The main contributions of this paper are the NCLOS methodology itself, as well as extensive work on default value development. The paper further provides an example application to an urban street segment case and a two-lane highway facility, with the latter offering interesting insights in the behavior of the three different performance measures in that method. Overall, NCLOS is a powerful tool to allow quick planning-level assessment of the capacities of various road segments.

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• Supplemental Notes:
  • This paper was sponsored by TRB committee AHB40 Highway Capacity and Quality of Service.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Findley, Daniel J
  • Chang, Jeffrey C
  • Vaughan, Christopher L
  • Schroeder, Bastian J
  • Foyle, Robert S
  • Alford, David Michael
• Conference:
  • Transportation Research Board 93rd Annual Meeting
  • Location: Washington DC
  • Date: 2014-1-12 to 2014-1-16
• Date: 2014

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 21p
• Monograph Title: TRB 93rd Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Highway capacity; Level of service; Methodology; Network analysis (Planning); Performance measurement; Sensitivity analysis
• Uncontrolled Terms: Default values
• Geographic Terms: North Carolina
• Subject Areas: Highways; Operations and Traffic Management; Planning and Forecasting; I72: Traffic and Transport Planning;

Filing Info

• Accession Number: 01520797
• Record Type: Publication
• Report/Paper Numbers: 14-0168
• Files: PRP, TRIS, TRB, ATRI
• Created Date: Apr 2 2014 9:40AM