Cary, N.C. — To alleviate long delays with school buses that have irked parents this week, the Wake County Public School System said Friday that an extra 27 school buses would be on the road by next Tuesday.

Complaints have poured into the school district's offices since traditional-calendar schools started classes on Monday about buses getting students to school late and not bringing them home for hours after classes have dismissed – and some that never showed up at their assigned stops.

More than 900 Wake County school buses transport 75,000 to 80,000 students per day and make about 25,000 stops. The district took dozens of buses out of service this year to cut costs while maintaining efficiency.

The district must keep a level of efficiency – a formula that compares different districts across North Carolina determines efficiency – to keep millions of dollars in state funding.

Superintendent Tony Tata said Friday, however, that more buses are needed to ensure students are taken to school and returned home in a timely manner.

“There are no excuses for what happened, and we are committed to fixing the problem,” Tata said in a statement. “If we determine more buses are needed, we will continue to add them until the issue is resolved.”

The school district added four buses to its routes on Tuesday and another seven on Friday. Sixteen more buses will be on the roads Tuesday morning, officials said.

School principals were expected to communicate Friday with parents of students affected by changes to bus routes and schedules. The new bus routes also will be posted on the school district's website.

Each extra bus costs the school district $70,000, district spokesman Mike Charbonneau said. The district also could lose about $3.5 million in state efficiency funds because of the additional buses, he said.

The Wake County Board of Education plans to discuss the bus situation at its meeting next week, and officials said the board also will look at the related funding issues.