No-show drivers, forcing students to miss school completely.

Extended delays, making kids late.

Long, illogical routes, trapping special needs children on buses for hours.

For many families, the first two weeks of the school year have been marred by infuriating problems with school bus service. 

"It's absolutely unacceptable, the transportation issues we've had this year. It's unacceptable," said Schools Chancellor Richard Carranza.

The city's yellow school bus system is notoriously plagued by problems every September as new routes take effect and drivers, both new and returning, get acclimated. But this year, it's been especially bad. 

A complaint hotline operated by the Office of Pupil Transportation has logged more than 76,000 calls, up from more than 57,000 at this point in the last school year. And that's just the angry parents who can get through.

"I want to apologize to families and our students and say to them, 'Listen, I hear you. We hear you. We're working hard.' But it's unacceptable," Carranza said.

Many of the problems are in Queens. The principal of PS 166 in Astoria sent parents emails last week saying bus service was so broken, children should be picked up. Other principals sent simliar messages. 

Routes managed by Grandpa's Bus Company, part of the Logan Bus Company, have been especially troubled. The city put Grandpa's on notice Friday, warning if drivers fail to pick up any children this Monday, those routes will be reassigned to other carriers. 

The chancellor says he's learned that bus problems are almost part of the back-to-school routine here. 

"This is my first start of the school year in New York City. It's given me an opportunity to kind of experience what happens, and one of the things I will absolutely not let happen is, 'Oh, this just happens at the start of every year.' That's absolutely not OK," Carranza said. 

One hundred and fifty thousand kids ride yellow buses in the city, and two-thirds of them have special needs. About 5,000 homeless children take the buses to and from shelters.

The City Council education committee said it will hold a hearing on the problems.