Approximately 8 per cent of male drivers have defective colour vision. It is commonly assumed that they have difficulty in the recognition of road traffic light signals, but the nature and extent of their difficulty is not known or have theoretical predictions as to the best colours for traffic lights been tested under conditions simulating road traffic signal lights. Normal and colour defective observers identified 13 colours as either red, green or amber. Each colour was presented 16 times under 2 levels of surround luminance. The colours were representative of the chromaticity boundaries established by the C.I.E. and by the Nation Standards A.S.A. D 10-1 1958 and B.S. 1376 : 1953 Errors and choice reaction timed were measured. Analysis of reaction times is presented. Analysis of error scores is not yet complete. The surround luminances used did not affect reaction times. Choice reaction time findings are found to be consistent with theoretical prediction from facts concerning defective colour vision.
Abstract