Assessing the performance of the SpeedInfo sensor.

Details

• Creators:
  Coifman, Benjamin ; Kim, Seoungbum
• Corporate Creators:
  Ohio State University
• Corporate Contributors:
  United States. Federal Highway Administration
• Subject/TRT Terms:
  • Freeways
  • Traffic data
  • Data collection
  • Performance measurement
  • Loop detectors
  • Sensors
  • Traffic surveillance
• Publication/ Report Number:
  FHWA/OH-2013/21
• Resource Type:
  Tech Report
• Geographical Coverage:
  Ohio
• Corporate Publisher:
  Ohio. Dept. of Transportation. Office of Statewide Planning and Research
• Abstract:
  Until recently freeway traffic operations data were collected in house by the Ohio Department of ; Transportation (ODOT) using loop detectors. In recent years several private companies have emerged with a ; viable opportunity to outsource traffic data collection. While these new business models and ease of ; deployment are compelling, there are few published studies explicitly evaluating their performance. ODOT has ; contracted with two of these data providers: SpeedInfo and INRIX. This study exploited a unique juncture as ; ODOT transitioned to the new third party data collection: the two new systems and the legacy loop detectors ; were concurrently operational in Columbus, OH for approximately 6 months. Using the archived data from this ; period, we evaluated SpeedInfo and INRIX performance over a 14 mi. This long period of time ensured that we ; would have a better chance of observing intermittent features that might go unobserved in a short-term study. ; Both SpeedInfo and INRIX traffic data generally performed within specifications, exhibiting small biases ; that could likely be fixed with fine-tuning. Both sensors also exhibited a reporting lag, on the order of 60 sec for ; SpeedInfo and 360 seconds for INRIX (comparable to conventional 60 sec and 5 min aggregation periods used ; in loop detectors). Although the lag and bias are within specifications, some applications might be sensitive to ; them, e.g., traffic responsive ramp metering. Each system also exhibited unique behavior not found in the other. ; SpeedInfo is sensitive to precipitation: sometimes going offline for tens of minutes. When mounted on the ; shoulder, SpeedInfo showed slightly degraded performance on the far side traffic. INRIX reported speeds every ; minute, but after excluding repeated values, the actual effective reporting period was more like 3-5 min, with ; occasional periods of repeated measurements lasting in excess of 10 min (already reflected in the lag above). ; INRIX also provides two measures of confidence, neither of which reflects the measurement repetition.
  More +
• Format:
  PDF
• Funding:
  State Job Number 134723
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/26979/dot_26979_DS1.pdf
• File Type:
  [PDF - 15.05 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:1937021f91ff9e47e81b5e48cf5234903e18356eee850509a6428f04418aa8e6