Manhattan District Attorney Cy Vance brought charges yesterday against 30 people accused of selling and using fake parking placards.

“New York City is one of the most expensive and challenging places in the world to park a car,” Vance said in a statement. “I hope this indictment sends a clear message to anyone using a fake parking placard in Manhattan that this behavior is illegal and may result in a criminal prosecution.”

It’s good whenever law enforcement takes placard abuse seriously, and the cases announced Tuesday will hopefully discourage others from engaging in placard fraud. But there’s only so much the DA can do here.

The vast scope of placard abuse — both the misuse of legitimate parking permits by government employees, and the culture of “professional courtesy” that extends free parking perks to anyone with an official-looking emblem on the dashboard — is largely beyond the reach of a crackdown on clever counterfeits. Only a concerted effort by the mayor and NYPD can make a dent in the routine placard abuse that clogs streets and sidewalks, imposing real costs on the public.

Placards are theoretically intended to help government workers conduct government business. In practice, though, they allow people to leave a car just about anywhere with virtual immunity from law enforcement, whether they’re on the job or not.

Last spring, City Hall told Politico there were roughly 160,000 city-issued placards in existence. The MTA, Port Authority, the Office of Court Administration, city district attorneys, and the governor’s office all issue placards as well. Few agencies would talk to Politico about how many placards they’re allotted, and none would disclose who gets them.

Mayor de Blasio has shown little interest in addressing placard abuse in any meaningful way. To the contrary, he ensured it would get worse when he reissued tens of thousands of permits the Bloomberg administration had taken away from Department of Education employees, increasing the number of city placards by almost 50 percent.

“We’re not going to tolerate misuse by city employees, we’re not going to tolerate private citizens who fabricate placards or misuse,” de Blasio said of Tuesday’s arrests. “I think it’s a good example of the fact more and more enforcement is happening and anyone who inappropriately uses a placard or fabricates a placard will pay a price.”

The arrests by Vance and NYPD are a welcome development, but de Blasio is muddling the issue by claiming these fake placards are representative of placard abuse broadly speaking. Much more common than a detailed forgery are parking violations committed with real placards, or the use of informal signifiers of authority to scare away enforcement agents.

Well, since this @NYPDDetectives had such a polite note, it's no problem making room by parking illegally in the bike lane mixing zone. pic.twitter.com/nDeUt1gOXd

— placard corruption (@placardabuse) October 4, 2017

Despite the mayor’s tough talk, illegal parking by both types of placard abusers remains rampant.

Ultimately, the only surefire way to get rid of placard abuse is to get rid of placards. The fewer the better. Failing that, de Blasio and his NYPD should at least be transparent about the official placards in circulation and regularly report on the extent of abuse — and enforcement — in a manner that independent observers can verify.