The buses were listed as "out of service until repaired" because of safety defects.
School systems are required to inspect every bus every 30 days. Once a year, safety inspectors from the North Carolina Department of Public Instruction look at 10 percent of the buses in every county.
They use a 400-item checklist on every bus and also go on a road test. Each bus gets a score based on "defect points." Ideally, a bus should have no defects and a score of zero.
But some Wake County buses fell well short of that. For example, an inspection report for bus number 962 has a whopping 189 defect points. That's five times higher than the average defect score in eastern North Carolina of 37.09 points.
Bus 962 failed the state inspector's braking system test. It had a broken rear bumper, a broken brake light, and a list of other problems.
"Something fell through the cracks. Either someone wasn't doing their job, or it got missed," said Derek Graham who is responsible for the school bus safety program at the North Carolina Department of Public Instruction. "It's very rare to see that many defect points."
During the Wake County safety audit last May, the inspector ordered a total of 28 buses out of service while looking at just 10 percent of the total county bus fleet. In his report, he wrote:
"This same percentage when applied to your entire fleet is 280 school buses that could have issues such that they should not be operated for transporting students."
A total of 14 buses - or half of the ones pulled off the road - had more than 100 defect points, like bus number 962.
Don Haydon is Chief Facilities and Operations Officer at Wake County Public Schools. ABC11 asked him about the inspections report and the mechanics responsible for maintaining the county buses.
He told us mechanics that aren't taking care of buses are first given warnings and if necessary put on an improvement plan. The ultimate punishment can be disciplinary action leading to firing.
"Some individuals have been terminated," he said.
To put Wake County's problems in perspective, ABC11 examined records at the Charlotte-Mecklenburg school district. It's the other large district in the state operating more than 900 buses a day.
In its recent safety audit, Charlotte had an average of 25.73 defect points per bus. Wake County averaged 51.31 - or twice as many. Nine percent of Charlotte's buses were pulled out of service compared to Wake's 30 percent.
But Haydon told ABC11 it's not necessarily a fair comparison.
"I think it's difficult to compare because there's two different inspectors doing that," he said.
Haydon said Wake is focused on making things better.
"What the inspection results indicate is that we still have work to do, and we're dedicated to doing that," he said.
The Wake County scores have been improving in recent years. In 2009, the average defect score was 78.96 - more than two times higher than the 38.38 average for districts in eastern North Carolina.
In 2010, the score improved to 54.53. This year it's 51.33 - with zero being the perfect score and a bus with no defects.
Asked if the district has everything it needs to maintain buses, Haydon said mechanics might say they need more workers and different facilities, but:
"I don't think there's a need to make any excuses," he said.
Haydon told us the county's aim is "making sure that all buses are safe for children."
North Carolina imposes no penalty on school districts no matter how many safety problems turn up in annual inspections.
It has recently trained and certified 800 bus safety inspectors who work as school districts in the hope that they will help school systems identify problems in their own monthly inspections.