The most basic flaw in the New York State traffic justice system is that in most cases it fails to hold motorists accountable for deadly recklessness. Unless a motorist is under the influence of alcohol or drugs, killing someone with a car is usually not considered a crime.

In a column for the Times, Barron Lerner, whose 9-year-old nephew Cooper Stock was killed by a cab driver in Manhattan this month, says it’s time to treat reckless driving like drunk driving. “Reckless driving, circa 2014, is what drunk driving was prior to 1980: it is poorly defined in the law, sometimes poorly investigated by police and almost never results in a criminal charge,” he writes.

An NYU professor and author of “One for the Road: Drunk Driving Since 1900,” Lerner writes that today’s attitudes toward everyday recklessness resemble societal and legal norms during the decades when efforts to criminalize drunk driving were met with “cultural indifference.”

Well into the 1970s, police and prosecutors looked the other way, seeing drunk drivers either as diseased alcoholics, young men sowing their wild oats or, paradoxically, victims themselves, even if they killed or maimed people. Judges and juries — perhaps because they, too, secretly drank and drove or knew those who did — were reluctant to convict.

Police told family members that their loved ones — the actual victims — had been “in the wrong place at the wrong time.” Crashes were called accidents.

This is, of course, exactly how law enforcement reacts to crashes like the one that killed Cooper Stock, who was in a crosswalk with his father when both were hit by a cab driver who reportedly took a turn without slowing down. No charges were filed against the driver, and no action was taken against his hack license.

“The police reassured my brother-in-law, Dr. Richard G. Stock, who was holding Cooper’s hand at the time of the crash, that a Breathalyzer done at the scene was negative,” Lerner writes. “Yet merely looking for alcohol or drug involvement by the driver misses the point.”

In the 80s, Lerner writes, collective action by parents and other loved ones, through groups like MADD, forced a “sea change” that brought about laws that toughened penalties and lowered legally acceptable blood alcohol levels. Their activism also attached a social stigma to driving drunk, making the public realize that “drunk drivers were still responsible for the damage they caused, even though the harms they inflicted were unintentional.”

Lerner says a similar shift is needed if New York City is to achieve Vision Zero. “If Cooper died because an impatient or distracted driver made a careless decision, then that driver should be as guilty of a crime as someone who drank alcohol or used drugs before driving,” he writes. “Let’s make destruction caused by irresponsible driving a true crime. And let’s do it soon.”