N.J. Stat. § 39:3-53
A motor vehicle may be equipped with no more than one spot lamp, but the use of any such spot lamp for driving purposes is prohibited and every lighted spot lamp shall be so aimed and used so as not to be distracting or glaring to any person. The provisions of this section shall not apply to authorized emergency vehicles, or to incident management response team vehicles or safety service patrol vehicles.
For the purposes of this section:
"Incident management response team vehicle" means a vehicle operated by the Department of Transportation or by a private entity under contract with the department which is equipped to respond at any time to assist the State Police with highway incidents.
"Safety service patrol vehicle" means a vehicle operated by the department or by a private entity under contract with the department consistent with the provisions of subsection (m) of section 5 of P.L. 1966, c.301 (C.27:1A-5), which is equipped to respond to highway incidents and provide assistance to motorists in disabled vehicles during designated hours in designated coverage areas in the State.
N.J.S. § 39:3-53