FOG ACCIDENT PREVENTION STUDY: VISIBILITY OF COLORED LUMINOUS AREAS IN FOG. FINAL REPORT

A SERIES OF SUBJECTIVE VISIBILITY TESTS, PERFORMED WITH LUMINOUS-AREA, RED-LIGHT SOURCES OF DIFFERENT SIZES IN ARTIFICIALLY GENERATED FOG, SHOW THAT IN DAYTIME FOG OF 50-FT VISUAL RANGE AND NIGHTTIME FOG OF 100-FT VISUAL RANGE, THERE WAS APPRECIABLE DIFFERENCE IN VISIBILITY BETWEEN 2-IN. DIAMETER AND 6-IN. DIAMETER SOURCES OF EQUAL INTENSITIES IN NIGHTTIME FOG OF 500-FT VISUAL RANGE, THE LARGER SOURCE WAS FOUND TO BE SOMEWHAT MORE VISIBLE THAN THE SMALLER ONE. ANOTHER SERIES OF SUBJECTIVE TESTS WERE PERFORMED UNDER VARIOUS VISIBILITY CONDITIONS TO DETERMINE THE VISUAL DETECTION CONTRASTS FOR RED, AMBER AND GREEN LUMINOUS AREA TARGETS VIEWED AGAINST CORRESPONDINGLY COLORED BACKGROUNDS. THE RESULTS SHOW THAT UNDER CLEAR-WEATHER CONDITIONS DAYTIME OR NIGHTTIME, THERE WAS AN APPRECIABLE DIFFERENCE IN TARGET-TO-BACKGROUND DETECTION CONTRAST FOR THE THREE COLOR. IN FOG OF 100-150 FT VISUAL RANGE, HOWEVER, THE DETECTION CONTRAST WAS GENERALLY LOWER, FOR THE RED TARGETS THAN FOR THE GREEN WITH THAT FOR AMBER BEING INTERMEDIATE BETWEEN THE OTHER TWO COLORS. THESE DIFFERENCES WERE MORE PRONOUNCED IN DAY-TIME FOG THAN IN NIGHTTIME FOG OF THE SAME DENSITY. /SRIS/

• Supplemental Notes:
  • 35pp, 15fig, 4TAB, 7REF
• Corporate Authors:

  University of California, Berkeley

  Vehicle Technology Facility
  ,   United States 
• Publication Date: 1969-4

Subject/Index Terms

• TRT Terms: Color vision; Daylight; Fog; Light; Luminosity factor; Night; Night visibility; Prevention; Psychological tests; Range (Statistics); Safety; Size; Testing; Vehicle range; Visibility
• Uncontrolled Terms: Light sources
• Old TRIS Terms: Luminosity; Subjective tests
• Subject Areas: Highways; Safety and Human Factors; Security and Emergencies;

Filing Info

• Accession Number: 00221046
• Record Type: Publication
• Source Agency: Nat Safety Council Safety Res Info Serv
• Files: TRIS
• Created Date: Nov 18 1970 12:00AM