Context-Sensitive Signage Design
"From the point of view of local government, the regulation of signs is motivated by the need to ensure public safety and minimize the negative visual impacts of signs in a community. The means by which these goals have traditionally been accomplished have been to limit the size of signs, control their type, placement, and appearance, and, generally, to impose measures to reduce 'visual clutter.' It is usually not the impact of any one business sign that motivates municipalities to adopt sign regulations, but the long-term, cumulative impact of many private signage decisions."
Thanks to American Planning Association