Work vehicle warning lights : color options and effectiveness.

Details

• Creators:
  Howell, Brian ; Pigman, Jerry ; Agent, Ken
• Corporate Creators:
  University of Kentucky Transportation Center
• Corporate Contributors:
  Kentucky. Transportation Cabinet
• Subject/TRT Terms:
  Color Construction And Maintenance Equipment Light Emitting Diodes Recommendations Surveys Vehicle Lighting Systems Warning Systems
• Publication/ Report Number:
  KTC-15-06/SPR15-57-7-1F
• Resource Type:
  Tech Report
• Geographical Coverage:
  Kentucky
• Corporate Publisher:
  University of Kentucky Transportation Center
• Abstract:
  KTC reviewed existing regulations, guidance, and practices to assess the Kentucky Transportation Cabinet’s warning
  
  lights program on highway work vehicles. The Kentucky Revised Statutes categorizes KYTC vehicles as “public safety
  
  vehicles” and requires their use of amber lights. Because the use of red can be confused with emergency vehicles,
  
  KYTC prohibits the use of red on work vehicles. At the national level, standards for warning light colors do not exist.
  
  Rather, AASHTO provides guidance on roadway operations equipment and recommends the use of amber and white
  
  lights as the primary warning light colors for highway vehicles. AASHTO guidance also prescribes the use of slow,
  
  asynchronous flash frequencies; LED light sources; and placement of lights at high elevations and against solid-colored
  
  backgrounds. The MUTCD provides little guidance in terms of warning light specifications, including color preferences.
  
  A review of existing state agencies, including DOTs, concluded that amber and white are the primary light colors
  
  currently in use across highway operations vehicles.
  
  KTC conducted two external surveys to assess warning light products and practices within the U.S. The first survey
  
  reviewed vendor LED products and revealed that LED lights are primarily available in the colors of amber, blue, green,
  
  red, and white. Fluorescent yellow-green is not available. The second survey requested state DOT information related to
  
  lighting systems’ colors, sources, intensity, and placement; responding agency names and policies; and previous state
  
  DOT studies related to warning lights. Survey responses indicated 100 percent use of the color amber (as a color type) as
  
  well as use of LED light sources. More than 75 percent of reporting agencies place warning lights on their highway
  
  work vehicle’s roof to maximize visibility to motorists. Survey results varied dramatically on the differentiation of
  
  warning light colors by vehicle type and the differentiation of light intensities for daytime versus nighttime conditions.
  
  KTC researchers recommend the use of amber and white colors for KYTC work vehicles, an asynchronous flashing
  
  pattern with slow flash frequencies, and LED bulbs. Other recommendations include placement of warning lights at high
  
  elevations on the vehicle, placement of warning lights against a solid-colored background, and investigation on
  
  feasibility of yellow-green LED lights
  
  
• Format:
  PDF
• Funding:
  SPR15-57-7-1F
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:94201ab2cc04480b4d44a29a9db51da129042954fb5c15ced4c5f6bec959f26c
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/29552/dot_29552_DS1.pdf
• File Type:
  [PDF - 2.28 MB ]