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RECOGNITION OF REFLECTING VEHICLE LICENSE PLATES WITH VARIOUS REFLECTION VALUES FROM THE STANDPOINT OF POLICE USE

NCJ Number
64775
Author(s)
ANON
Date Published
1978
Length
32 pages
Annotation
THE RECOGNITION PERFORMANCE OF WEST GERMAN REFLECTING LICENSES PLATES OF VARYING REFLECTION VALUES IS TESTED.
Abstract
IN 1975, CHIEF TRAFFIC OFFICERS OF THE NETHERLANDS, BELGIUM, FRANCE, LUXEMBOURG, SWITZERLAND, AUSTRIA, AND THE FEDERAL REPUBLIC OF GERMANY DETERMINED THAT IN THE INTEREST OF TRAFFIC SAFETY ALL EUROPEAN MOTOR VEHICLES SHOULD BE EQUIPPED WITH REFLECTING LICENSE PLATES. THE INTERNATIONAL CENTRE FOR CRIME AND ROAD ACCIDENT PREVENTION (AFFILIATED WITH THE INTERNATIONAL ASSOCIATION OF CHIEFS OF POLICE) TESTED HOW WEST GERMAN LICENSE PLATES OF STANDARD SIZE AND VARYING REFLECTION VALUES (REFLECTION COEFFICIENTS OF THE WHITE BACKGROUND AMOUNTING TO 035, 054, 082, 103, 130, AND 234 CAND/LUX PER SQUARE METER) MET CONCRETE POLICE REQUIREMENTS. THE TEST SITUATIONS INCLUDED (1) RECOGNITION FROM A STANDING POLICE VEHICLE AT A DISTANCE OF 20 TO 30 METERS AT VARYING CAMERA POSITIONS, (2) RADAR SPEED CHECKS WITH VARYING CONTROL EQUIPMENT (DIFFERENT BRANDS) AND AT VARYING SPEEDS, (3) PHOTOGRAPHS OF RED LIGHT VIOLATIONS, (4) VEHICLE DISTANCE MEASUREMENTS, AND (5) FRONT VIEW SHOTS AT VARYING SPEEDS AND CAMERA POSITIONS. THE TEST PHOTOGRAPHS TAKEN ON A CLEAR NIGHT (AND SUPPLEMENTED BY VARIOUS BAD WEATHER TESTS) SHOWED LITTLE DIFFERENCE IN THE PERFORMANCE OF THE DIFFERENT REFLECTION VALUES. EITHER LICENSE PLATES OF ALL REFLECTION VALUES WERE CLEARLY RECOGNIZABLE, OR ALL REFLECTION VALUES WERE ILLEGIBLE. ONLY IN A FEW SITUATIONS DID PARTICULAR REFLECTION VALUES PRODUCE PHOTOGRAPHS OF BETTER QUALITY. THE MAJOR DIFFERENCES IN RECOGNITION LAY IN THE TYPE OF EQUIPMENT USED (BRAND OF CAMERA, CONTROL EQUIPMENT, TYPE OF FILM) OR IN THE PARTICULAR TECHNIQUES OF FILM DEVELOPMENT (E.G., BLOW-UPS). THE 61 PHOTOGRAPHS TAKEN IN THE TEST SERIES ARE APPENDED. --IN GERMAN. (SAJ)