Kudos to Chancellor Richard Carranza for taking ownership of the city school bus mess. He’s got a lot to clean up if he means to avert the same old chaos next year.

Susan Edelman gave a taste of the swamp that is the Office of Pupil Transportation in Sunday’s Post, revealing that 25 top OPT staff — many with little-to-no field responsibilities — had scored taxpayer-funded city cars, which they used to . . . commute to work, in clear violation of city rules. (OPT revoked the perks after The Post got on the story.)

Such rampant privilege fits for an agency that seems content with year-after-year bus snafus for thousands of city kids, including toddlers delayed for hours in their rides to and from school. Maybe OPT can use the savings from the canceled cars to do a few dry runs before school actually opens.

Carranza has also put the Office of Special Investigations in charge of probing misconduct allegations against bus drivers and attendants. And he’s reassigned Elizabeth Rose, who’d been deputy chancellor in charge of school transportation: Edelman reported in April that Rose had raised eyebrows by slashing penalties and reversing dismissals of misbehaving drivers and attendants.

On the other hand, Rose wasn’t demoted, but kicked sideways to a job “advising” Carranza. What message does that send to all the OPT workers who are beyond frustrated with the annual disasters?

Mayor Bill de Blasio, meanwhile, blamed this year’s snafus on the need to bus homeless kids to school from faraway shelters. Strange: City Hall had been bragging about how it’s gotten homeless families into shelters closer to their home neighborhoods.

Carranza can’t take that as license for his own excuse-making. Having taken direct control of OPT, his mission is clear: End the favoritism and self-dealing, sniff out corruption — and put the children’s needs first.

Then again, that’s what’s needed across his entire department . . .