Assessing Accuracy of Roundabout Analysis Procedures Against Field Observations: Preliminary Results from Case Study in Northern New England

The recent interest in using modern roundabouts as an effective and safe method for intersection control all around the United States points out to the need for accurate modeling tools to aid in their planning, design and analysis. The main objective of the current paper is to assess the accuracy of select analytical and microscopic simulation tools for roundabouts analysis, by comparing their output to detailed field observations. On the analytical side, the study focuses on the two most popular analytical models in use in the U.S., namely aaSIDRA and RODEL. For microscopic traffic simulation, the study considers the PARAMICS model developed by Quadstone Limited. The study focuses on one representative case study for a roundabout in Nashua, New Hampshire. The selected roundabout, however, is observed for a large number of time intervals and under different traffic conditions in order to yield an adequate number of data points that can be used for evaluation. The research illustrates some of the numerous challenges in comparing roundabouts analysis models’ output to field observations, including difficulties in measuring field delay and relating the measured values to the different delay types reported by the different models. In addition, preliminary results show that PARAMICS delay estimates are about 4 seconds/vehicle lower than the field. For the analytical models, aaSIDRA’s estimates are generally close to field measurements, whereas RODEL’s estimates are about 10 seconds/vehicle higher.


  • English

Media Info

  • Media Type: CD-ROM
  • Features: Figures; Photos; References;
  • Pagination: 18p
  • Monograph Title: TRB 86th Annual Meeting Compendium of Papers CD-ROM

Subject/Index Terms

Filing Info

  • Accession Number: 01047615
  • Record Type: Publication
  • Report/Paper Numbers: 07-2868
  • Files: TRIS, TRB
  • Created Date: Feb 8 2007 7:34PM