Your business is subject to the sign code written and enforced in your community. Sign codes can be different from one place to the next. For instance, the city of Long Beach, CA, prohibits signs mounted on rooftops (a very common clause in sign codes), and mechanical signs.
Some codes tightly regulate business signs, out of concern that they can put drivers at risk (by being too distracting, or by keeping you from noticing traffic signs).
However, these studies show that business signs by themselves don't cause traffic accidents:
Customers in their cars would be hard-pressed to spot this market’s sign at night.
In 1998, Richard N. Schwab, a former program manager within the U.S. Federal Highway Administration, stated that "[t]raffic safety is not jeopardized by the sign itself or some sort of stimulus overload; instead the culprit is inadequate sign size or lighting, or inappropriate placement, or a combination of these factors."
In 1985, the "Pennsylvania Tort Claims Study" concluded that "signing deficiency" (or the failure to provide information in a safe and efficient manner, when and where a driver needs it) was a factor in 22% of serious vehicle injury cases.
A sign in a community with a strict code can meet its legal requirements, but in reality be too small, or badly placed, or poorly lit for passing drivers.
Traffic safety can be improved when drivers are told where they are in relation to where they want to go, and telling them where it's safe to park.
