Unless New Jersey lawmakers decide otherwise, drivers under age 21 will continue to have to display little red decals on their license plates if they want to remain street legal.

The state Supreme Court on Monday upheld “Kyleigh’s Law,” finding the decal requirement does not violate the federal Driver’s Privacy Protection Act or federal and state constitutional guarantees of privacy and equal protection and against illegal searches and seizures.

“The policy arguments for and against [the law] are not for this Court to consider, but are properly made before the Legislature. It is not in our province to determine the wisdom of this statute or to weigh its value to police officers in enforcing [the law] against any safety concerns that are raised by the decal requirement,” the court unanimously ruled in Trautmann v. Christie, A-16-11.

Kyleigh’s Law, which took effect May 1, 2010, is named for Kyleigh D’Alessio, a 16-year-old killed in a 2006 Morris County crash in which another teen was driving.

It requires drivers under age 21 to display reflective decals on the upper left corner of the license plate, sets limits on the number of passengers in the car and generally bars them from the road between 11 p.m. and 5 a.m.

The statute was challenged by a Rockaway attorney, Gregg Trautmann, on behalf of his son, Douglas Trautmann, and another teenager, Thomas Struble.

Trautmann argued the statute violates the federal Driver’s Privacy Protection Act, 18 U.S.C.A. §§ 2721-2725, which prohibits states from releasing drivers’ personal information, such as Social Security numbers, telephone numbers and home addresses.

In addition to the privacy and constitutional issues, Trautmann also argued that the decals make underage drivers more vulnerable to criminals in that they advertise the fact that an automobile is being driven by someone of tender years.

But the Division of Criminal Justice, in an interim report released last year, said only one instance of an underage driver being targeted by a potential predator had been reported. A 17-year-old girl was stopped by a purported policeman who turned out to be an imposter. The man, driving a dark vehicle with a flashing blue light, was wearing police-style uniform pants and a T-shirt saying “POLICE.” He asked the girl for her driver’s license, saying he was “a cop,” and said, “I saw the sticker on your car … and figured you were a hot 17-year-old.” He asked for her telephone number, but she refused to give it. At that point, he returned her license, said he was not a cop and was just kidding and left. Police were unable to find the man.

Both Morris County Superior Court Judge Robert Brennan and the Appellate Division dismissed Trautmann’s case, and the Supreme Court affirmed.

Kyleigh’s Law “requires the disclosure of nothing more than the fact that a driver is under twenty-one and is the holder of a special learner’s permit, examination permit or probationary license,” the court said, adding that an age group is not “highly restricted personal information.”

The court also rejected Trautmann’s assertions that the statute violates federal and state equal protection guarantees because the intrusions are minimal and serve a legitimate government need — providing an enforcement mechanism in an effort to maintain highway safety.

“There is, in this case, an ‘appropriate governmental interest suitably furthered by the differential treatment involved,’” the justices said, quoting Barone v. Department of Human Services, 107 N.J. 355 (1987).

Similarly, the justices dismissed arguments that the statute violates the privacy rights guaranteed under the Fourth and Fourteenth amendments to the U.S. Constitution and Art. 1, ¶ 7 of the state constitution.

Underage drivers “have no reasonable expectation of privacy in their age group, because a driver’s age group can generally be determined by his or her physical appearance, which is routinely exposed to public view,” the court said. “Further, because the decal required … is affixed to the exterior of the car, in plain view, an officer’s review of that decal does not constitute a search.”

The court added, though, that “the presence of a decal does not exempt police officers from the obligation to comply with constitutional safeguards in conducting a traffic stop.”

Failure to use the decal can lead to a $100 fine. In May, the Associated Press reported that police had issued approximately 1,800 summonses on underage drivers who were not displaying the decals.

Trautmann says he will ask the U.S. Supreme Court to hear an appeal.

“The court was reading the Driver’s Privacy Protection Act too narrowly,” he says. “That statute is meant to be read broadly. The clear purpose is to protect drivers by not giving out that private information. A driver’s age is just the type of information the statute was designed to protect.”

D’Alessio’s mother, Donna Weeks, was allowed to participate as amicus. Her attorney, Joseph Bell Jr., who also runs a firm in Rockaway, says he is not surprised by the ruling.

“The issues had been fully addressed by the Appellate Division,” says Bell. “This case is emblematic of democracy in action. Ms. Weeks petitioned the Legislature and convinced [lawmakers] that this law would be appropriate and would save lives.”

Paul Loriquet, a spokesman for Attorney General Jeffrey Chiesa, said, “We are pleased with the court’s decision, which affirms that neither the federal nor state constitution was violated by the state’s exercise of its authority to impose reasonable requirements on youthful drivers in furtherance of the public safety.”

A bill to repeal the decal requirement, S-1578, sponsored by Republican Senators Jennifer Beck of Monmouth County and Christopher Bateman of Somerset County, is pending before the Senate Transportation Committee. No hearings have been scheduled.