Nearly 100,000 students in Louisville, Kentucky are staying home Thursday and Friday after their school district's new transportation system stranded some of them for hours.

Jefferson County Public Schools, which transports about 68,000 students a day, made changes to the system after a driver shortage caused significant delays last year. This year's new system, which uses artificial intelligence, was supposed to work with fewer drivers but things didn't go well on Wednesday.

Some students were stuck at school for hours after dismissal, with school staff staying late to supervise them. The last student didn't get home until nearly 10 p.m.

In a video posted Thursday morning, district Superintendent Marty Pollio apologized for the "transportation disaster" and said cancelling school for the rest of the week was one of the most difficult decisions of his career.

Here's what you need to know about what happened:

What is the new system?

The district spent $199,000 to hire the AlphaRoute engineering firm to create a plan that would cut the number of bus routes and stops following a driver shortage last year that led to students being late for classes and sometimes stranded after school.

AlphaRoute uses artificial intelligence to map the system's routes, allowing the district to use a smaller number of routes than drivers for the first time in several years.

The change, as explained by district leaders over the past several months, was to move schools to a staggered start time schedule, going from two school start times to nine and eliminating the need for drivers to make multiple runs to the same school in the morning and afternoon.

What caused the 'transportation disaster?'

In a Thursday morning email sent to families, the district said the new transportation plan "did not live up to our standards."

Pollio told parents in an email that there are always issues on the first day of school but what happened was "unacceptable." He said the problem "will be fixed."

"In years past, most of the kinks in the transportation system have been worked out within two weeks," he said. "We’re hopeful that will be the case again this year."

Pollio also requested everyone to show bus drivers "some grace and understanding" as they have been working hard to understand the routes and their students.

Actual details regarding what went wrong haven't been shared. There were significant issues in the morning with late buses, buses not showing up at stops and students ending up at the wrong school.

Things went far worse in the afternoon. Students were left stranded at school while they waited for the buses to pick them up and drop them home, leaving parents worried.

A parent of a 5-year-old student, who was supposed to be dropped off at 5:20 p.m. told The Courier Journal that her daughter still had not arrived at 7 p.m. The bus depot number had a voicemail indicating there was a high volume of calls and she would have to try again later, she said.

"I'm worried sick about my baby," the parent wrote through a Courier Journal bus delay form. "I don't know where she is or who to call at this point. What if she is lost?"

Other parents took matters into their own hands and collected their children from school themselves.

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Buses still running throughout county

Despite school closure, district buses are driving throughout neighborhoods Thursday morning so that drivers can work through the closure to get further practice on their routes, district spokeswoman Carolyn Callahan said.

"We will use the next four days to fix issues associated with the new transportation plan in order to ensure the safety and well-being of our students and staff," the district posted on X, formerly known as Twitter.

District employees also received a message that said the "new transportation plan was not executed as expected yesterday and we must improve."

It also said that for the next four days, bus drivers would be paid to practice their routes to "become more familiar with their runs and stops."

It is unclear how much practice drivers were given ahead of the new school year. The new plan was approved in March.

The district transports about 70% of its roughly 96,000 students across the 380-square-mile county each day. More than a dozen of its schools cover more than two-thirds of the county with its routes. In the 2021-2022 school year, the district spent $47 million on transportation.

Why did the district cancel school for all students?

The reason is Louisville's laws, which call for equal access to education for all, meaning the district can't open schools for some students who have the means to get there while others cannot.

District authorities said that Thursday and Friday will be treated as traditional snow days, with no non-traditional instruction and that it would contact families if there were changes to child-enrichment programs.

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Contact reporter Krista Johnson at [email protected].