Parents used subways, carpools and other alternatives to get their children to school, hitting slippery roads as sleet turned to rain around the city and temperatures were at or above freezing.

Peter Curry's 7-year-old daughter Maisy is in a wheelchair and is usually picked up by a bus with a ramp. On Wednesday he drove her from lower Manhattan to her school in the Chelsea section of the city.

"It means transferring her to the car, breaking down the wheelchair, getting here, setting up the wheelchair, transferring her from the car, when normally she would just wheel right into the school bus," Curry said. "She's on oxygen. There's a lot of equipment that has to be moved and transferred also."

On Staten Island, Tangaline Whiten was more than 45 minutes late delivering her second-grade son to Staten Island Community Charter School, after first dropping off her daughter at Public School 60 about six miles away.

She said the distance and the extra traffic on the road made the prospect of a long strike upsetting, because it means her son would be consistently late. If the strike lasts, she said she'll consider carpooling.

"Most of the parents where I'm at are working parents, so they're finding it difficult to transport their kids, and especially to pick them up," Whiten said. "I'm just fortunate that I'm a stay-at-home mom."

Wednesday's walkout was by the largest bus drivers' union; some bus routes served by other unions were operating.

Most of the city's roughly 1.1 million public school students take public transportation or walk to school.

Those who rely on the buses include 54,000 special education students and others who live far from schools or transportation.

The city has put its contracts with private bus companies up for bid, aiming to cut costs. The Local 1181 of the Amalgamated Transit Union says drivers could suddenly lose their jobs when contracts expire in June.

In an industrial part of Queens' Ridgewood neighborhood, several dozen union members showed up to stand in the cold rain in front of the Amboy Bus Company.

"Union! Power!" they chanted, pumping their fists into the air.

The city planned to distribute transit cards to students who can take buses and subways and to reimburse parents who would have to drive or take taxis.

"We will get our children to school," Walcott said.

The union announced Monday it would strike amid a complicated dispute.

The city doesn't directly hire the bus drivers and matrons, who work for private companies that have city contracts. The workers make an average of about $35,000 a year, with a driver starting at $14 an hour and potentially making as much as $29 an hour over time, according to union President Michael Cordiello.

Mayor Michael Bloomberg has said the city must seek competitive bids to save money.

The union sought job protections for current drivers in the new contracts. The city said that the state's highest court, the Court of Appeals, has barred it from including such provisions because of competitive bidding laws; the union said that's not so.

Asked if the city is prepared to go as long as the last school bus strike in 1979 which lasted 14 weeks, Walcott said on WINS Radio, "This will go however long it goes. We have systems in place to support our parents and students."

Walcott, who was making the rounds of radio and television news shows Wednesday morning, told WNBC-TV there were no talks scheduled.

"We're not negotiating. They want us to do something illegal. We can't do that at all. We're always open for communication … It's not our responsibility and job to negotiate. They work for private companies."

Asked if the city planned to take the striking union to court, Bloomberg told Fox 5 New: "I don't think it's time to do that" and characterized the union's actions as illegal.

"How is it illegal to provide the most experienced drivers and matrons in the school buses?" Cordiello asked Tuesday.

The contracts expire June 30.