Development of a statewide online system for traffic data quality control and sharing.

Details

• Creators:
  Wang, Yinhai ; Corey, Jonathan ; Lao, Yunteng ; Wu, Yao-Jan
• Corporate Creators:
  Transportation Northwest Regional Center X (TransNow) (UTC)
• Corporate Contributors:
  Washington (State). Department of Transportation ; United States. Department of Transportation. Office of the Secretary
• Subject/TRT Terms:
  Quality Control Traffic Flow--Washington (State)--Data Processing--Quality Control Traffic Flow Vehicle Detectors Vehicle Detectors--Washington (State)--Data Processing--Quality Control
• Publication/ Report Number:
  TNW2009-12
• Resource Type:
  Tech Report
• Geographical Coverage:
  Washington
• Edition:
  Final research report.
• Corporate Publisher:
  Transportation Northwest (TransNow) UTC
• Abstract:
  The Washington State Department of Transportation (WSDOT) operates thousands of Inductive Loop
  
  Detectors (ILDs) on the freeways and highways of Washington State. The collection and disbursement of
  
  this data is handled at the regional level, which has led to formatting differences and data fragmentation.
  
  The Datamart Project is intended to consolidate data from all regions and store it in one location easily
  
  searchable and accessible by all authorized users. Therefore a database and a web site have been created
  
  in a computer application called Datamart to accomplish these tasks and demonstrate the idea.
  
  Additionally, this research project has been also tasked with creating software applications for traffic
  
  sensor data acquisition and developing error detection and correction methodologies for data quality
  
  control. Error detection is accomplished in a three-step test proposed by this study to identify loop
  
  detectors suffering from severe errors. The default conditions used by this test approach are general
  
  enough to be applied in other states. Meanwhile, the approach also has its flexibility to use site specific
  
  parameters to optimize its performance at a specific location. These severe errors identifiable by this
  
  approach include wrong mode setting, cross chatting, extreme under sensitivity, and incorrect sensitivity
  
  level, among others. Loop detectors suffering from incorrect sensitivity levels may be adjusted by the
  
  proposed correction methodology. The correction methodology is designed to identify the true length of
  
  the loop detector’s detection zone. Properly calibrated ILDs are generally assumed to have detection zone
  
  sizes determined by the size of the loop coil buried in the roadway. The reality is that when ILD
  
  sensitivity levels drift from their correct settings, the detection zone size changes. By using the correct
  
  detection zone lengths, loop detector measurements can be corrected. This software-based approach is
  
  proven effective and can be retroactively applied to archived data as well.
  
  The loop error identification and correction algorithms have been implemented in the prototype
  
  Datamart system, which is an online database system backed up by Microsoft SQL Server 2008 and the
  
  Google Map technologies. It is highly scalable and has the potential to add new data sources from other
  
  transportation agencies and online analysis functions for regional transportation planning, traffic
  
  management, and analysis purposes.
  
  
• Format:
  PDF
• Funding:
  DTRT07-G-0010
• Collection(s):
  University Transportation Centers US Transportation Collection
• Main Document Checksum:
  urn:sha-512:02897496a868c0c8c51cf2edfc95a9d5e7f616a79c4a730f4ff90031077872890f9222293e011e4f16286f2e008973ded7a2d83652ce631e5e3ab4169b7460b3
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/5711/dot_5711_DS1.pdf
• File Type:
  [PDF - 1.50 MB ]