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:
  • Traffic flow
  • Vehicle detectors
  • Quality control Traffic flow--Washington (State)--Data processing--Quality control
  • 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.
  More +
• Format:
  PDF
• Funding:
  DTRT07-G-0010
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/5711/dot_5711_DS1.pdf
• File Type:
  [PDF - 1.50 MB]
• Collection(s):
  University Transportation Centers ; US Transportation Collection
• Main Document Checksum:
  urn:sha-512:02897496a868c0c8c51cf2edfc95a9d5e7f616a79c4a730f4ff90031077872890f9222293e011e4f16286f2e008973ded7a2d83652ce631e5e3ab4169b7460b3