As shootings of unarmed black men by the police have set off a national discussion on race relations and the way officers treat civilians, police departments across the country have struggled with how to make changes. Some departments, including in New Jersey, have adopted body cameras, required implicit-bias and de-escalation training for officers and held many meetings with local leaders.

In developing the Safe Stop campaign, Mr. Porrino said that much of the reform effort in New Jersey had focused on law enforcement, but that little had been done to educate the public.

“I have the power to direct law enforcement,” Mr. Porrino said. “I don’t have the power with respect to civilians, but I said to the team, ‘Shouldn’t we be thinking about ways to provide information that helps the other participants in every one of these encounters?’” A website that is part of the campaign allows people to file complaints against the police.

But some critics say providing people information about the rules they are expected to follow does not always ensure a safe encounter. DeRay Mckesson, a civil rights activist and one of the most recognized voices in the Black Lives Matter movement, pointed to the killing of Philando Castile, a black motorist in Minnesota who was fatally shot by a police officer while he was in his car during a traffic stop. Mr. Castile was shot moments after he told the officer that he possessed a firearm.

“These ads perpetuate the false narrative that when citizens are harmed in police-citizen interactions that the responsibility to mitigate harm rests with the citizen,” Mr. Mckesson said. “Philando Castile, for instance, did everything right and was still killed.”

The ads also stop short of fully explaining the rights of a citizen in a traffic stop, according to Harlan Yu, the executive director of Upturn, a nonprofit that studies how technology affects social issues.