L&D Manual Turn Lane Storage Validation/Update

Details

• Creators:
  Eustace, Deogratias ; Ponnada, Sowjanya
• Corporate Creators:
  University of Dayton. Department of Civil and Environmental Engineering and Engineering Mechanics
• Corporate Contributors:
  Ohio. Dept. of Transportation ; United States. Federal Highway Administration
• Subject/TRT Terms:
  Intersections Queuing Traffic Congestion Traffic Flow Turning Lanes
• Publication/ Report Number:
  FHWA/OH-2012/13
• Resource Type:
  Tech Report
• Geographical Coverage:
  Ohio
• Edition:
  Final report.
• Corporate Publisher:
  Ohio. Dept. of Transportation. Office of Research and Development
• Abstract:
  Queuing occurs at intersections mostly due to overflow or inadequacy of turn bays. The ODOT L&D
  
  Manual Volume 1 has storage requirements for both signalized and unsignalized intersections. Figures
  
  401-9E and 401-10E of the L&D Manual provide the required turn lane storage lengths which should be
  
  compared with the real world conditions to check for adequacy of these lengths as a measure of ensuring
  
  that accesses to the left turn lanes are not blocked. In addition to the projected turn lane volume, ODOT’s
  
  methodology incorporates both deceleration (based on the speed of the roadway) and potential blockage
  
  from the adjacent through lane. Currently, however, there are no records whether these storage lengths
  
  computed by the methodology put forth in this manual are valid and accurately represent the actual
  
  conditions at intersections in Ohio. This study used real world traffic and queue storage data at some
  
  intersections and analyzed these data to validate the model ODOT is currently using. This study used the
  
  observed field data to evaluate the ODOT’s model of storage length at intersections. In addition, the
  
  queue storage lengths observed from field data were compared with the prediction results of HCS and
  
  SYNCHRO computer packages. The model evaluation task evaluated the level of precision of each of the
  
  three models (ODOT, HCS, and SYNCHRO) with respect to the field data observation. L&D Manual
  
  lead the way by accurately predicting the observed queues by about 81.6% and closely followed by HCS,
  
  which also had a 79.2% prediction accuracy. SYNCHRO was by far the lowest with a 46.0% prediction
  
  accuracy.
  
  
• Format:
  PDF
• Funding:
  134573
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:4f1a219324e2766888c414d5625685e2605c0b757be527a994f7446bb324e21e
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/24934/dot_24934_DS1.pdf
• File Type:
  [PDF - 951.77 KB ]