Preparations for a potential Charleston school bus driver strike revved up Wednesday with officials encouraging the community to get ready.

Charleston County Schools Superintendent Nancy McGinley described the threat of a driver strike as “highly possible,” and she encouraged parents to start thinking about other transportation options for their children.

“We want parents to be alert, aware and thinking of alternatives,” she said. “We want to make sure our community is aware that in the event of a bus strike, there will be additional cars on the road.”

Union bus drivers in the Charleston and Dorchester 2 districts have been negotiating a new employment contract with their employer, Durham School Services, since last summer.

Charleston and Dorchester 2 bus drivers’ unions have authorized their leadership to call a strike, but union officials have set no deadline for a deal.

L.D. Fletcher is president of Teamsters Local 509, which represents drivers in Beaufort, Charleston and Dorchester 2. He could not be reached for comment Wednesday, but a Washington, D.C.-based spokeswoman for the national Teamsters organization released a statement that read:

“We understand that the state is trying to make sure the buses keep running. No one wants to see a strike, and we are working very diligently over difficult issues at the bargaining table to try to prevent that.”

Formal talks in Charleston Monday and Tuesday did not result in a deal, and the focus was supposed to shift Wednesday to Dorchester 2.

The biggest issue has been pay, but neither side will discuss any details. The average Charleston bus driver is paid $14.65 per hour for 4.5 hours of work each day.

Charleston district officials have said the union requested a roughly 44 percent pay and benefit increase for the first year of a three-year deal, but they said Wednesday those figures might have changed. Fletcher has said those numbers were wrong.

On Wednesday in Columbia, the state Board of Education approved 10-0 an emergency regulation that would help school districts continue to provide bus service if a strike occurs.

The state board temporarily waived some certification requirements for out-of-state drivers that would allow them to fill in for those on strike. These drivers still would have to have their commercial driver’s licenses, but they wouldn’t have to go through the state’s training program.

State Superintendent of Education Mick Zais said there was little the state could do to resolve the dispute, and he encouraged both sides to continue their negotiations.

“But I urge the Teamsters Union not to strike, because a strike will negatively affect parents and students,” he said.

Durham School Services officials haven’t released any statements since last week, citing the ongoing nature of the negotiations. Its chief executive officer, David Duke, wrote a letter this week in response to McGinley’s request that the company take whatever steps necessary to avoid a strike.

Duke wrote that he was “extremely disappointed” in the union’s vote to authorize a strike, and that he was aware of the need to treat employees fairly while balancing the long-term interests of the school district.

“In spite of the unrealistic demands and displeasing actions of the union, we are doing all we can to avoid service disruption for the students of Charleston,” Duke wrote.

Mike Bobby, Charleston schools’ chief of finance, operations and human resources, said the district was working with Durham on as many contingency plans as possible. It would be the district’s desire to avoid closing schools if drivers strike, he said.

“We know that more than 50 percent of our students don’t use the district’s transportation system, and it’s our intention to figure out how to support others who do,” he said.

Dorchester 2 schools spokeswoman Pat Raynor said district leaders were monitoring the progress of the drivers’ negotiations, and it also was looking at back-up transportation options. The district hadn’t contacted parents yet, but she said they would when officials had more information. Roughly 16,000 of the district’s 24,000 students ride a bus.

Reach Diette Courrégé Casey at @Diette on Twitter or 937-5546.