N.J. Stat. Ann. § 39:4-124

The State Highway Commissioner and local authorities, with reference to highways under their respective jurisdictions, may modify the method provided in section 39:4-123 of this Title, of turning at intersections by clearly indicating by buttons, markers or other direction signs, within an intersection, the course to be followed by vehicles turning therein. No driver shall fail to turn in the manner so directed when such direction signs are installed by said authorities.