The driver of a Greyhound bus filled with about 40 former prison inmates abandoned the vehicle Thursday along a highway because her hours for the day were over, police said.

There are strict rules about the number of consecutive hours that bus drivers can work, Greyhound officials said, according to the associated Press. The woman who was transporting the men from Huntsville reached her maximum about an hour west of their destination.

She pulled over in front of the Shamrock convenience store on East Dr. Martin Luther King Jr. Boulevard around 4 p.m. and told passengers her allotted driving time was up and another driver was on the way. Then she boarded another bus and left.

A clerk at the convenience store called the Corsicana Police Department and let them know about the stranded bus shortly after 5 p.m.

“In 31 years in law enforcement I’ve never seen anything like this,” Corsicana Police Sgt. Lamoin Lawhon said quoted by the AP.

Officers found the former prisoners walking around the bus, talking with one another, many of them quite anxious to continue their trip to Dallas. A second bus and three bus drivers arrived shortly after 7 p.m. to get the parolees back on the road.

Greyhound spokesperson Dustin Clark said company officials were investigating the incident. “It a very serious matter,” he said, according to the same source.

There were no incidents involving the passengers while they were stranded.