‘No Jobs Available’: The Feast or Famine Careers of America’s Port Drivers.

Fat clouds hang low over the Arrowhead, a landmark notched in the foothills of the San Bernardino Mountains, as Mr. Jackson arrives at the Mattel warehouse just after noon. He drops the container, picks up an empty, and returns to the freeway, headed back to the port for the second half of his long day.

Many truck drivers obsessively consume caffeine, perpetually fearful that they might otherwise descend into a dangerous state known as highway hypnosis.

Mr. Jackson abstains. “I drink a lot of this,” he says, taking a swig from a bottle of Fiji water.

To stay alert, he relies on the vibrations of his $6,000 sound system. He cranks up the dial on an old Isley Brothers classic, “Work to Do.” “I’m taking care of business, woman can’t you see. I’ve gotta make it for you, and gotta make it for me.”

He rolls past a billboard for, past tent cities full of homeless people, past self-storage units.

He makes it to the port in time for a meal before his 3 p.m. pickup.

He winds through the cracked streets of Long Beach, looking for a curb long enough to park a tractor-trailer. He finds a spot around the corner from the truck stop. He waits for an Uber Eats driver, who arrives bearing a Chipotle bowl — brown rice, chicken and avocado.

He drops the container, picks up another, and parks again in Long Beach, taking a nap in the back in the cab while waiting for rush hour traffic to ease.

At 6:30 in the evening, twilight settling over the parched land, he rolls toward home while again on the phone with his wife.