Evaluation of a real-time travel time prediction system in a freeway construction work zone : executive summary.

Details

• Creators:
  Zwahlen, Helmut T.
• Corporate Creators:
  Ohio. Dept. of Transportation. Office of Traffic Engineering ; Ohio University
• Subject/TRT Terms:
  • Travel time
  • Work zone safety
  • Route guidance
  • Travel time (Traffic engineering)--Mathematical models
• Resource Type:
  Tech Report
• Geographical Coverage:
  Ohio
• Edition:
  Executive summary.
• Corporate Publisher:
  Ohio. Dept. of Transportation
• Abstract:
  A real-time travel time prediction system (TIPS) was evaluated in a construction work ; zone. TIPS includes changeable message signs (CMSs) displaying the travel time and ; distance to the end of the work zone to motorists. The travel times displayed by these ; CMSs are computed by an intelligent traffic algorithm and travel-time estimation model ; of the TIPS software, which takes input from microwave radar sensors that detect the ; vehicle traffic on each lane of the freeway. Besides the CMSs and the radar sensors, the ; TIPS system includes the computer and microcontroller computing the travel times, ; 220 MHz radios for transmitting data from the sensors to the computer and from the ; computer to the CMSs, and trailers with solar panels and batteries to power the radar ; sensors, CMSs, and radios. The evaluation included an accuracy analysis between the ; predicted and actual recorded travel times and a survey of the motoring public. Three ; crews driving independently of each other in the traffic stream recorded predicted and ; actual travel times at three CMSs to the end of the work zone for 12 hours each day for ; three consecutive days, resulting in 119 trial runs. The data recorder in each crew also ; recorded the license plate numbers of private non-commercial vehicles with Ohio license ; plates. A total of 3177 different license plate numbers were recorded and a questionnaire ; was sent to each one. A total of 660 completed surveys were returned and analyzed. ; Based on the regression analysis of actual times vs. predicted times, the system does on ; the average a reasonable job in predicting the travel times to the end of the work zone. ; About 88% of the actual times recorded for each sign, and for all the signs combined, ; were within a range of ±4 minutes of the predicted time. However, a few differences ; (actual-predicted) as great as 18 minutes were observed. Survey responses indicated that ; the motoring public does perceive a certain inaccuracy in the travel times. However ; almost 97% of surveyed motorists felt that a system to provide real-time travel time ; information in advance of work zones is either outright helpful or maybe helpful. In ; summary we may conclude that the real-time TIPS system represents a definite ; improvement over any static non-real-time display system. It provides in general and ; most of the time useful and relatively accurate travel time predictions to the motoring ; public and appears to be perceived by the motoring public as a helpful addition to a ; freeway construction zone.
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• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/17515/dot_17515_DS1.pdf
• File Type:
  [PDF - 66.00 KB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:aba7512d9543a4e92ec6bc8657726785496a44119ef35bc1dceac87bd11163c3