Type faces with fairly heavy and uniform strokes are most legible. In addition to aiding legibility, liberal negative space, when enclosing the copy creates a target on which the viewers eye can focus quickly. This is especially important for glance legibility. Signs, just as highways, should be designed and constructed for the individual with poor vision, rather than for the average person. Signs should be designed, constructed and placed for easy readability.
Pedestrian oriented and motorist oriented signs have difference criteria of design.
This proportion varies depending upon color of lettering and background. Capitals are seen more quickly, but lower case letters can be read more rapidly, a point to remember when preparing copy for motorist oriented signs along highways and freeways. Inter-letter spacing increases letter and word legibility. This is especially important to motorist- oriented signs. The effect of stroke width definitely affects legibility, but is related to letter size and spacing.