Cyclists have got to start considering how to protect themselves from the idiocies of the mayor.

In his weekly conversation today with WNYC’s Brian Lehrer, the putative “Bike Mayor” had a hard time explaining why he’s considering licensing and helmet requirements for cyclists.

Instead of discussing how such laws would promote safety (hint: they don’t), de Blasio launched into a fact-free word salad, saying he wants to “consult with everyone” on street safety.

He also told a caller:

“There also are problems protecting folks who use bikes and e-bikes and also maybe someday scooters, and making sure everyone follows rules so everyone else is protected including the most vulnerable folks who are pedestrians. So we’re gonna look at all that, and there’s gonna be a public discussion of it and we want to think about what’s going to keep people safe.”

Huh?

It’s one thing for the mayor to give an off-the-cuff answer on a subject he hasn’t thought about. But but by now he’s seen the tons of coverage highlighting how his brainless suggestion will hurt street safety.

As traffic expert Charles Komanoff bluntly put it: “Helmet laws marginalize cycling and isolate cyclists instead of improving road safety for all; they also fail on their own terms by suppressing safety in numbers, raising the likelihood that cyclists will suffer serious-injury accidents.”

We will say it again: The administration left the building when the boss sidled onto a campaign bus. Apparently, no one told de Blasio that researchers at Virginia Tech warn that “there’s no way for consumers to tell the difference between a helmet that skated by and one that passed with flying colors.” Nor did anyone bother to put in front of him his own DOT’s research saying that cycling got safer in the city because more people are doing it.

Lives are at stake on the streets. The cyclists who are getting doored into trucks and hit by speeding drivers aren’t dying because they failed to wear bright clothing at night or a $20 hunk of styrofoam and plastic. They’re dying because they have to share the road with two-or-more-ton killer machines operated by an entitled class that only thinks about itself — if it thinks at all.

The mayor, who can’t even escape getting dumped on for his driving habits on the Tucker Carlson White Power Happy Hour, is going to have to learn that at some point. Except that he himself seems to view life through a windshield.

Digging in on a bad idea is by now a hallmark of the mayor’s late-administration behavior, so we probably shouldn’t have expected him to approach the bike-helmet question with any intellectual probity.

But if you don’t have anything smart to add to a conversation, just don’t say anything at all.