Citation

Case HW, Michael JL, Mount GE, Brenner R. Highw. Res. Board bull. 1952; 60: 44-58.

Copyright

(Copyright © 1952, National Research Council (U.S.A.), Highway Research Board)

DOI

unavailable

PMID

unavailable

Abstract

Destination signs of maximum legibility are needed for the development of highspeed urban freeways. A survey was made of the literature on one factor thought to influence low legibility which is the letter-background arrangement with the usual alternatives being black letters on a white background and white letters on a black background. This survey indicated that an investigation should be made in a field situation to attempt to determine whether or not outdoor, daylight letter legibility varies with letter-background arrangement, and how this legibility is influenced by spacing between letters and roads. Black letters on a white background and white letters on a black background were compared with respect to legibility. Both closely spaced and widely spaced signs were used. The subjects were divided into four levels of visual acuity.

RESULTS indicated that the widely spaced letters were more legible than those closely spaced, and that the legibility of the black-white arrangement as compared with the white-black arrangement was dependent on the letter spacing. This interaction was discussed in terms of irradiation and fixation fluctuations, and these concepts were then used to infer the effects of decreasing stroke width. These inferences were limited to the closely spaced letters.