While driving, a motorist has a 20° range, or "cone of vision." If your business has a sign whose setback (i.e., its distance) from the road is outside of this cone, then your sign is in danger of being missed.

The angle at which someone sees your sign influences how much time a driver needs to react to the sign. A sign at a 90° angle to the road would be the best option, while those parallel to the road are the hardest for drivers to see. In this table, Type I refers to signs that are at a 90° to the road, while Type II signs are those that are parallel to the road. See the difference in square footage?

Sign Size Guidelines for On-Premise Signs
		Type I	Type I	Type II	Type II
SPEED LIMIT (miles/hour)	LANES OF TRAFFIC	SIGN SIZE (sq. ft.)	HEIGHT (feet)	SIGN SIZE (sq. ft.)	SIGN HEIGHT (feet)
25	2	25	12	50	12
25	4	32	12	70	12
35	2	36	20	75	20
35	4	42	20	90	20
45	2	75	35	100	40
45	4	90	35	120	40
55	2	150	50	250	90
Urban Freeway		300	74	450	90
Source: Schwab, Richard N.