Kayley, a student at Central Park East 2 (with head turned), traveled to school with his mother today. He took a city bus instead of a yellow bus because of a strike by school bus drivers.

Families across the city contended with unfamiliar transportation routes, incomplete information, and bad weather to get their children to school this morning, the first during a strike called by the bus drivers union.

Most bus drivers did not report to work today to protest the city’s decision not to extend seniority protections to current drivers when opening bids for new contracts with bus companies. Their union, Amalgamated Transit Union Local 1181, also picketed outside some bus depots, in some cases briefly impeding non-union bus companies from operating, and released a television ad that paints new bus drivers as dangerous.

But the Department of Education said 40 percent of buses actually did roll today, including 100 percent of routes serving children in prekindergarten. Those bus drivers work under contracts negotiated last year.

Just 12 percent of routes for students in general education were running today, while 60 percent of routes serving students with special needs were disrupted.

Preliminary data showed strong attendance citywide, Chancellor Dennis Walcott announced at a city press conference where he praised parents for “being really focused on getting their kids to school.” But he said attendance at District 75 schools, which serve the city’s most disabled students, was down by about a quarter today.

Just over half of students made it to P811 in Manhattan, down significantly from the 90 percent average daily attendance rate, according to teachers there. Teachers at a Staten Island school, P721, reported similar figures.

A security guard who works in the housing project near the New York Center for Autism Charter School in Manhattan said he had not seen as many kids as usual arriving at the school this morning.

One mother, Lucia, said she made the commute by taxi from Tribeca — at great personal expense. Her son’s autism makes him unable to take public transportation. Even though the the city will reimburse the $31 cab fare each way, she will still lose four hours a day shepherding her son to school, going to work, picking him up, and returning home.

“The strike delays my workday by two hours. I have to transport him morning and afternoon,” she said. “So that’s four hours of unproductive time for me in terms of work. I only have four hours there, and what can I do in four hours?”

(The city’s reimbursement plan requires parents to front the costs of transportation by car for a week. “But what if parents don’t have any money?” asked Crystal, a teacher at an early learning center. “You’ll reimburse them, but who’s going to give them the money to get there?”)

Students arrive at the New York Center for Autism Charter School this morning. Many students who attend the school take buses whose drivers started a strike today.

Another mother at the school, who identified herself only as Grace, said she spent an hour and a half in traffic this morning with her son. “It’s terrible, and I’m going to be late to work,” she said.

At Central Park East 2, an unzoned school where many students take the bus, a mother named Carla said her flexible schedule meant bringing her children was not a problem today. But, she said, “it’s harder for [other] parents, especially the parents who work 9 to 5. … It’s a bad day out, too.”

Other students stayed home. Barbara, who works at P.S. 306 in East New York and asked that only her first name be used, said her daughter stayed home today. Tomorrow, she said, her daughter would be late to P368, a school for students with disabilities in Cobble Hill. “I have to get her to school when I get off at 9:30,” she said.

And dropping two of his siblings off at P.S. 306 before getting on the city bus to Urban Action Academy, Ricardo Medina said his other younger brother stayed home because his special education school was too far away.

“They’re really mad but I guess there’s nothing they can do if the bus people are going on strike,” Medina said about his parents.

The Department of Education has created a search tool for families to find out whether their school’s buses are running as usual. But some families evidently did not find out in time that their children’s buses would not be disrupted by the strike.

At P.S. 306, Principal Lawrence Burroughs said the school was operating normally because most students live nearby. But of the four buses that normally serve the school, just one showed up today, and it was empty, according to a school safety officer.