Any road trip with a small child might turn out to be a trial. But if the kid is as manic as the little Iranian boy in “Hit the Road,” there’s no doubt about it.

He is wound-up, loud, blurting a dozen thoughts and a hundred questions an hour, crawling over the seats, hiding the family cell phone, playing with the dog in the back, distracting the driver and driving his 50ish father out of his mind.

“Punk,” “little fart” and “little s–t” he calls this hyperactive four year old fruit of his loins. He’s only half-kidding. The kid’s doting mother just pleads, “Can you just shut up?“

But the boy is only four, with the vocabulary of a poet, or a wit.

“BLISS!” he shouts into the wind, standing up with the sunroof open as they cross one arid vista after another.

He won’t give back the phone without a fight. “If I don’t answer my calls, people will worry!”

Dad, in a cast and denied any hope of taking a nap, even when they park to take a nap, makes threats that are to be taken seriously. Sort of.

“Before I die, here is my last will and testament!” the little imp announces.

As amusing as he is, if everybody’s a little frazzled, a bit on edge and occasionally morose in the debut feature of Panan Panahi, we think we see the cause. But of course we don’t know the half of it. This isn’t a straightforward “road comedy.”

Mom (Pantea Panahiha) is worried that “We’re being followed,” (in Farsi with English subtitles). Every time the subject of “leaving” or leave-taking comes up, the older son/driver (Amin Simiar) pouts, snaps or storms off.

Dad (Hasan Majuni) is the one doing most of the wrangling and question answering duties with their irrepressible youngest, played by Rayan Sarlak as if every take begins just after a fresh belt of Red Bull. That’s because Dad is the one clinging to a sense of humor, for the annoying kid’s sake.

They’ve sold their house, we gather, and their car. This one is borrowed. The oldest son is in a jam and heading for the border. And little Jessy, their adorable dog in the back, is sick.

Every single one of those facts must be kept from the kid, who is so easily distracted — every toilet break or roadside stop becomes a frenetic, got-to-see-everything adventure — maybe they can pull it off.

They pass a peloton of bicycle racers, and the child so distracts one of the riders and his brother the driver, that they knock the poor fellow down. Giving him a lift means Dad’s going to poke at the guy’s “role model, on the bike and in life,” Lance Armstrong.

“Dishonest prick…”

A random woman comes up and snips a lock of older brother’s hair. A sheepskin most be bartered for, directions must be botched, getting them lost. And the kid drives most everybody they meet to some level of distraction.

He’s our distraction, too. Panahi makes this kid — an adorable moppet…when he’s sleeping (probably) — not so much the center of attention, but someone the characters and the viewer can focus on when things get heavy and sad. Which they do.

Perhaps the father is in denial about what this trip represents. His wife may be on the verge of tears, grasping at moments stolen with her oldest son. But Dad is looking to pass on advice, just to lighten the mood.

“Whenever you kill a cockroach, don’t throw him down the toilet,” he tells his oldest. “Remember, his parents sent him into the world with lots of hope!”

All along the way, we see stunning Iranian vistas and hear Iranian pop — bubbly or sad — as characters lip-sync to the radio.

Panahi spins all this into a road comedy with a bittersweet aftertaste, letting us laugh out loud at the travel companion from Hell — or at least “The Ransom of Red Chief” — while wistfully reminding us of loss and leave-takings, the helpless desperation of running afoul of an authoritarian state, the very foundations of heartbreak.

Rating: unrated, smoking, profanity

Cast: Pantea Panahiha, Hasan Majuni, Rayan Sarlak and Amin Simiar

Credits: Scripted and directed by Panah Panahi. A Kino Lorber release.

Running time: 1:34