Queue Warning and Travel Time Estimation near a Work Zone

The I-94 St. Cloud Intelligent Work Zone (IWZ) project provided travelers with travel time information and queue warnings for both westbound and eastbound I-94 from St. Cloud, Minnesota to Rogers, Minnesota during a 7.5 mile concrete overlay installation. A vendor was contracted to supply temporary roadside hardware and to generate and display travel times and stopped traffic advisories in the eastbound direction. The Minnesota Department of Transportation (MnDOT) provided a similar system for the westbound direction. The two systems were evaluated in terms of data accuracy and latency. The project team performed baseline data collection in the form of floating car studies and video vehicle re identification, conducted analysis using data from those methods, and provided weekly status reports to MnDOT that summarized data quality and suggested improvements. This paper describes the methodology used to compare the travel time and queue warning systems’ data with baseline data. The paper then presents the accuracy of these systems as compared to MnDOT’s accuracy thresholds as required from the vendor. In general, the queue warning system in both directions performed within the desired tolerances. However, the travel time algorithm for the eastbound (vendor-provided) system was modified to improve the travel time latency, adjusted to improve the travel time accuracy, and the detector data was smoothed to remove some variability in the reported travel times. The westbound (MnDOT) system generally performed consistently throughout the project. The paper also summarizes the process of reviewing interim findings on a weekly basis in order to identify performance issues and system modifications that that are needed to improve accuracy. Lessons learned and recommended modifications to MnDOT’s procurement specifications are provided. This paper provides valuable information on IWZ system performance targets and how they can measured, enabling transportation agencies to ensure that the public is provided with meaningful and accurate information.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AHB55 Work Zone Traffic Control.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Petersen, Scott
  • Minge, Erik
  • Iverson, Chris
• 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; Maps; Photos; References; Tables;
• Pagination: 17p
• Monograph Title: TRB 93rd Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Accuracy; Estimates; Queuing; Real time information; Travel time; Warning systems; Work zones
• Identifier Terms: Minnesota Department of Transportation
• Geographic Terms: Saint Cloud (Minnesota)
• Subject Areas: Construction; Highways; Operations and Traffic Management; I50: Construction and Supervision of Construction; I73: Traffic Control;

Filing Info

• Accession Number: 01515482
• Record Type: Publication
• Report/Paper Numbers: 14-4719
• Files: TRIS, TRB, ATRI
• Created Date: Feb 24 2014 8:42AM