Does the type of street (Street, Avenue, Road…) have to be on a Street Name Sign?
While it is tempting to not put the abbreviation designating street, road, avenue or the like on a Street name sign (D3-1) to shorten the sign, this is not recommended. While the MUTCD does not prohibit leaving the designation off, doing so would create confusion whether the sign is a Street Name Sign or a Hamlet Sign (NYI12-1). Since the primary users of the street name signs are those unfamiliar with an area, this confusion could have negative consequences.
Since the designation can be in a smaller font (3 inch versus 4 inch for typical 12 inch high signs), the extra length for a road or street (Designations “Rd” and St” respectively) would only be about 3 inches. Another alternative would be to use a different series font for the lettering. Series D and Series C are both equally acceptable, and B is allowed for unusually long street names. It is also allowed to reduce letter spacing by up to 20% to shorten the string length.