Heavy vehicle performance during recovery from forced-flow urban freeway conditions due to incidents, work zones and recurring congestion.

Details

• Creators:
  Drakopoulos, Alex ; Liu, Yue ; Horowitz, Alan
• Corporate Creators:
  National Center for Freight and Infrastructure Research and Education (U.S.)
• Corporate Contributors:
  United States. Dept. of Transportation. Research and Innovative Technology Administration
• Subject/TRT Terms:
  • Traffic speed
  • Freeway operations
  • Heavy vehicles
  • Headways
  • Car following
  • Passenger car equivalence
  • Highway capacity
  • Level of service
  • Traffic congestion
  • Traffic measurement
• Publication/ Report Number:
  CFIRE 04-17
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Corporate Publisher:
  National Center for Freight and Infrastructure Research and Education (U.S.)
• Abstract:
  Information contained in the Highway Capacity Manual on the influence heavy vehicles have on freeway traffic ; operations has been based on few field data collection efforts and relied mostly on traffic simulation efforts. In the ; 2010 Manual heavy vehicle impact is evaluated based on “passenger car equivalent” values for buses/trucks and ; recreational vehicles. These values were calibrated for relatively uncongested freeway conditions (levels of service ; A through C) since inadequate field data on heavy vehicle behavior under congested conditions were available. ; Field-collected headway information was based on the average headway for vehicles in a particular class, ; regardless of the type of vehicle they were following. ; The goal of the present effort was to collect and analyze freeway field data on headways with an emphasis on ; heavy vehicle behavior under lower speeds typically associated with a level of service E (capacity) or F (forcedflow ; conditions). Contrary to previous efforts incorporated in the Highway Capacity Manual methodology, that ; disregarded the effect a leading vehicle has on headways, headway information was collected for ten ; leading/following vehicle pair types containing at least one passenger car (for example buses followed by ; passenger cars). Headway statistics were analyzed for nine speed ranges (up to 20 mph; 20-25 mph; 25-30 mph; ; 30-35 mph; 35-40 mph; 40-45 mph; 45-50 mph; 50-55 mph; and 55+ mph) and ten vehicle pair types. ; Passenger car equivalent values were derived for each speed range based on the average headway for a specific ; vehicle pair type divided by the average headway between passenger cars. A total of 3,981,810 individual vehicle ; records were used to construct the 2,645,210 vehicle pair records for which headway statistics were compiled. All ; analyzed information originated from the Milwaukee County, Wisconsin urban freeway system. Leading and ; following vehicle class and speed were found to significantly influence headways and passenger car equivalent ; values.
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• Format:
  PDF
• Funding:
  244K672
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/27779/dot_27779_DS1.pdf
• File Type:
  [PDF - 3.01 MB]
• Collection(s):
  University Transportation Centers ; US Transportation Collection
• Main Document Checksum:
  urn:sha256:e7e072524cea0ec014e7b4246b607250a642145052106cfbae3ef3aebfca39f9