In May, New York City principals received letters from the advocacy group Asthma Free School Zone, urging them to keep trucks from their buildings. “Sometimes you’ll see a child in a stroller parked right next to the exhaust pipe of the truck,” said Lori Bukiewicz, schools coordinator for the organization, which has been trying to persuade Mister Softee to use biodiesel fuels in generators for their freezers and to get city officials to pass legislation controlling the trucks’ emissions. For the last two years, it has been illegal for ice cream trucks in the city to play their jingles while stopped for business.

Parents in most places improvise solutions  running the other way when they hear the jingle or telling their children that they left their wallets at home.

Rachael Reiley of Cambridge, Mass., called the ice cream truck “the music truck,” convincing her 3-year-old son that it was playing “The Entertainer” simply to entertain. But he soon got wise when he saw the other children walking away from the truck, their faces smeared with chocolate and vanilla, their hands filled with ice cream cones.

Image BAN THE BELL? Some parents dislike vendors near playgrounds. Credit... Jenn Ackerman/The New York Times

Ms. Reiley didn’t mind buying him a treat, occasionally. But the truck  called Here’s Frosty  parks outside her door on most sunny days around 4:30 p.m. and wakes her son from his nap. “Then he’s up, plastered against the window, yelling: ‘Music truck! Music truck!’ ” Ms. Reiley said. “Sometimes he grabs his little bank and says, ‘I have money.’ ”

As a new mother, she said, people coach you on potty training and what to feed your child. “But the ice cream truck, nobody ever mentions that,” she said.

In northeastern Wisconsin, on the social networking site Moms Like Me, a group of mothers shared their ice cream angst in June. “I was amazed at the number of moms who said they hated it,” said Laura Kaste, the site manager. For some, the cost was a problem. Another mother was angry that the ice cream man would always arrive right before dinner. Joel Semanko, who owns an ice cream vendor business, Cool Cycles, in Tacoma, Wash., said the dignified, responsible days of the ice cream man cruising into a neighborhood at dusk began to fade in the 1970s.