These images illustrate the difference between a daylight view of the two standard typefaces used on highway signs and the nighttime view with halation, as seen by an older driver, when high brightness sign materials are used.
Current freeway guide signs are based on a fixed measurement system adopted in 1958 (left). The example shown has over 31 measurements with great variation from sign to sign based on content. The new Proportion Based Grid System with Clearview Type System (right) optimizes the readability of the panel. Layout is based on only nine dimensions that are all a proportion of the primary legend. As size of the primary legend changes based on road speed and motorists viewing requirements, the panel can be adapted accordingly.
BEFORE: an old road sign.
AFTER: a new road sign with Proportion Based Grid System and the Clearview Type System.