PERCEPTION AND VISIBILITY OF AUTOMOBILE LICENSE PLATES

INCREASING MOTOR VEHICLE SPEEDS AND INTERSTATE TRAVEL EMPHASIZED THE NEED FOR EASY AND ACCURATE IDENTIFICATION OF VEHICLES UNDER VARIOUS TRAFFIC CONDITIONS, WHILE GROWING REGISTRATIONS TENDED TO CAUSE CROWDING OF LICENSE PLATES AND THE USE OF LEGENDS DIFFICULT TO PERCEIVE AND RETAIN. TESTS WERE DEVISED TO COMPARE THE MERITS OF PLAIN NUMERAL AND LETTER-NUMERAL SYSTEMS, VARIOUS SIZES AND STYLES OF LEGENDS, AND VARIOUS GROUPINGS, INCLUDING THE SO-CALLED "DEVINE" SYSTEM. BASED ON OBSERVATIONS BY 50 PERSONS OF SPECIALLY DESIGNED BLACK AND WHITE CARDS, 2,500 CAREFULLY CONTROLLED READINGS WERE OBTAINED. IT WAS FOUND THAT ALL SIX-CHARACTER COMBINATIONS WERE SUPERIOR TO SEVEN-DIGIT NUMBERS, THE USE OF LETTERS INCREASES THE DIFFICULTY OF PERCEPTION, AND GROUPING OF CHARACTERS BY TWOS OR THREES IMPROVES PERCEPTION. A GAIN IN VISIBILITY SEEMED TO RESULT WITH SIX AND SEVEN-CHARACTER PLATES WHEN THE "DEVINE" SYSTEM WAS USED. NO APPRECIABLE DIFFERENCE WAS NOTED BETWEEN ROUND AND BLOCK NUMERALS, BUT OPEN-TYPE NUMERALS WERE SUPERIOR TO BOTH. NUMERALS WITH A WIDTH ONE-HALF THEIR HEIGHT WERE MORE VISIBLE THAN THOSE WITH A SMALLER RATIO OF WIDTH TO HEIGHT. THE FLAT-TOP THREE WAS VERY FREQUENTLY MISTAKEN FOR 5, WHILE 8 AND 9 ALSO CAUSED CONSIDERABLE CONFUSION. /AUTHOR/

  • Supplemental Notes:
    • Vol 17, ParT I, PP 393 - 412, 1 FIG, 12 TAB, 9 PHOT; part of Report of Department of Traffic
  • Authors:
    • Aldrich, M H
    • Johnston, C M
    • Lauer, A R
  • Discussers:
    • Barnett, J
  • Publication Date: 1938

Media Info

  • Monograph Title: Proceedings of the Seventeenth Annual Meeting of the Highway Research Board Held at Washington, D.C. November 30, December 1, 2, 3, 1937. Part I
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00221010
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Aug 15 1971 12:00AM