LIGHTS AND LIGHTING FOR HAZARD WARNING AND DELINEATION

Hazard Warning Study - In a laboratory study 24 observers, representing a cross-section of driver ages, were asked to respond to a flashing yellow light, presented to scale in a simulated roadway setting amongst various other lights; both flashing and steady-burning. A field study was also conducted using both 6 and 12-v lamps, wherein observers were required to compare these lights at varying flash rates. It was found that a flash rate of between 95 and 105 flashes per minute, with an approximately 20 percent 'on time,' was preferred, with an effective intensity of a least 20 to 40 candela for a 1,000-ft warning distance. Delineation Lighting Study - In a laboratory study with 108 observers, and a field study using 20 observers, steady-burning lights proved distinctly superior to various types of flashing light delineation systems. For best delineation, the left and right rows of lights should be different colors.

• Supplemental Notes:
  • Study was aided by DOT, Federal Highway Administration.
• Corporate Authors:

  Michigan Department of State Highways & Transport

  Testing and Research Division
  Lansing, MI  United States  48904
• Authors:
  • Janson, M H
• Publication Date: 1976-10

Media Info

• Pagination: 97 p.

Subject/Index Terms

• TRT Terms: Field studies; Flashing traffic signals; Hazard markings; Highway delineators; Lighting; Simulation; Vision; Yellow interval (Traffic signal cycle)
• Uncontrolled Terms: Flashing yellow signals
• Old TRIS Terms: Delineators (Traffic)
• Subject Areas: Highways; Safety and Human Factors;

Filing Info

• Accession Number: 00158098
• Record Type: Publication
• Source Agency: Federal Highway Administration
• Report/Paper Numbers: FHWA-M1-76-928
• Contract Numbers: R-928
• Files: TRIS, USDOT, STATEDOT
• Created Date: Oct 13 1977 12:00AM