In the 1996 movie “Carpool,” a busy father’s turn driving the neighborhood kids to school goes haywire when a bank robber played by Tom Arnold takes the family minivan hostage. There’s bathroom humor, singing and a madcap detour through the local shopping mall. Hilarious.

For New Jersey Uber driver Zogie Ella, carpooling is no laughing matter. On days when she is drawn into Uber’s version of the venerable American tradition, known as Uber Pool, she says her anxiety skyrockets.

“It’s a feeling of not knowing whether or not your passengers are going to bond or clash over any little thing,” says Ms. Ella, 36 years old.

A couple of months ago, she picked up two customers who battled before her eyes.

“The second passenger got in and requested that I turn the radio on,” says Ms. Ella. “As I reached to turn it on, the first passenger said she preferred for there to be no music during the ride.”