Comprehension of some alternative forms of regulatory traffic signs.

SOME ALTERNATIVE FORMS OF SYMBOLIC REGULATORY SIGN FORMATS, INCLUDING THE MAJOR INTERNATIONAL ONES, WERE COMPARED IN TWO LABORATORY STUDIES WITH EACH OTHER AND WITH CURRENT AUSTRALIAN STANDARD SIGNS IN TERMS OF THEIR COMPREHENSION BY A BROAD RANGE OF AUSTRALIAN DRIVERS. FOR TURN RESTRICTION SIGNS, MANDATORY AND PROHIBITORY FORMS WERE ALSO COMPARED. THE BEST FORM OF SYMBOLIC MANDATORY SIGNS HAS A GREEN ANNULUS WITH THE WORK 'ONLY' APPENDED; FOR TURN RESTRICTIONS THIS FORM WAS SUPERIOR BOTH TO PROHIBITORY AND TO SIMPLE MANDATORY FORMS. IT WAS ALSO THE BEST OF THE BUS LANE SIGNS TESTED. THE BEST FORM OF SYMBOLIC PROHIBITORY SIGNS HAD A RED ANNULUS AND RED DIAGONAL SLASH. TO CONVEY A LIMIT, A RED ANNULUS WITHOUT A DIAGONAL SLASH WAS BETTER. HOWEVER, IT WAS FOUND THAT THE BEST COMPREHENDED AND MOST OFTEN PREFERRED SIGNS WERE THOSE CURRENTLY USED IN AUSTRALIA, ALMOST ALL OF WHICH INCLUDE A VERBAL STATEMENT OF THE SIGN MEANING. IT WAS SUGGESTED THAT THE OPTIMUM FORM OF REGULATORY SIGN IS THE 'HYBRID' COMBINING THE ADVANTAGES OF BOTH SYMBOLIC AND VERBAL INFORMATION CODING (A). THIS PAPER WAS ALSO PUBLISHED AS AUSTRALIAN ROAD RESEARH BOARD INTERNAL REPORT AIR 348-1. THE NUMBER OF THE COVERING ABSTRACT OF THE CONFERENCE IS IRRD NO 255423.