During the last two years in the california division of highways has experimented with the development and use of lower case letters for overhead destination signs on freeways. Recognition of word patterns is known to be fundamental in close reading of ordinary printed material and it was thought that habit and pattern factors might also make this form of letter desirable for highway signs. Opinion as to their effectiveness has been varied, however. The problem therefore was to measure the distance at which lower case signs could be read as compared to rounded capital letters. Experiments were undertaken to determine the distances at which signs of each kind of alphabet could be read. Letters from 5 in. To 18 in. In height were mounted on a bridge 17 ft. Above the ground and a total of 75 observers made 3939 individual observations under daylight and artificial illumination. /author/.
Abstract