Every 15 minutes for almost 15 hours each weekday, the Route 22 bus runs up and down State Street, pausing for passengers at 14 stops.

There's always the low rumble of the engine, the squeaky whine of the brakes. Doors open and then close with a slap.

Just a few seats behind the driver sits 18-year-old David Felipe Gomez in a plaid shirt and jeans, a tiny ring piercing his lower lip. One seat away is Chris Hopkin, wearing a yellow tie and polished shoes, and he rests one leg on the seat as he scrolls through a handheld computer.

In the Salt Lake area, an average of 56,000 people ride the bus each weekday. Most follow an unspoken code: You don't sit next to someone if an empty seat is available, and you generally don't talk or make eye contact. Riders will stare out the window, close their eyes, flip through a book or look at their cell phone.

Anywhere from 12 to 50 people ride the Route 22 bus at 8 a.m. It leaves each morning from the 6400 South TRAX station in Murray and ends at the Salt Lake City Intermodal Hub at 600 West and 200 South.

The bus brings people together who might otherwise never cross paths. Sometimes, schedules and lives will intertwine. Or people will get off the bus, to have their seats taken by others.

But what do they know of each other?

The driver

About five minutes before he's scheduled to leave at 8 a.m., Chuck Ackerson wanders outside the bus to talk with Tom Brotherson, a fellow driver who goes by "Tom Tom." Brotherson drives the 8:15 bus, just after Ackerson.

For more than 30 years, Ackerson has worked as a bus operator for the Utah Transit Authority. It's a job he says he fell into but enjoys. Toward the end of the Vietnam War, he was in a specialized program to become a pilot. But then the war ended, and "they didn't need us anymore," Ackerson says.

He took a job as a bus driver because he had a young family and needed to provide.

His mother and father are buried in Arlington National Cemetery. His father was a technical sergeant during World War II. His mother was eligible for burial in Arlington because of his father's service.

"I used to sit on President Taft's grave," says Ackerson, who grew up in Virginia but came to Utah after high school.