New Jersey Statutes Title 39. Motor Vehicles and Traffic Regulation 39 § 4-183.22a

(a) Shape--Rectangle with longer dimension horizontal;

(b) Color--White background with black letters;

(c) Dimensions--Four feet by six feet, or larger for higher approach speeds;

(d) Message--CONSTRUCTION AHEAD or other appropriate wording, the distance over which the warning applies, and the approved speed limit.

(e) Location--Where construction work is in progress within the roadway area, a construction warning sign shall be located on each side of the roadway, facing approaching traffic, five hundred feet to one thousand feet in advance of the beginning of the construction area, the distance depending on the approach speeds on that roadway.