Experiments In The Ordered Perception Of Coloured Cartographic Line Symbols

As part of a linked program relating to the design of maps for route planning, two experiments requiring some methodological improvisation were carried out. A psychophysical test using line symbol segments found that the perceived prominence of the individual symbols in central vision could be predicted remarkably consistently by a combination of measures of line width, brightness and saturation contrast, and the effective value of the line colour. A second performance-based test of line symbol conspicuity suggested a minimum colour difference to be used between line classes to prevent confusion in peripheral vision.