ACQUISITION OF INFORMATION FROM ALPHANUMERIC ROAD SIGNS

This paper was presented at Session 38 - Signing, Delineation and Guidance 2. Twenty observers read 109 alphabetic road signs when they were presented for brief periods between 250 ms and 2 seconds. Sixty of the signs were from the Australian standard and all have been in use in the traffic system. They varied in length from two words to 40 words. It was found that the time taken to correctly read a sign was approximated by the relation t=0.32n-0.21, where n is the number of words in the sign. Context afforded by the meaning of message allowed about 1.5 additional words to be read compared to random word reading; familiarity with the message gave similar gains. Layout of the words did not seem to be an important factor, at least for three-or four-word signs. The results show that while the resolution-limited predictive model described in a preceding paper describes performance for two-or three-word signs, performance increasingly falls short of that predicted for longer signs. (TRRL)