MINNEAPOLIS — Minnesota school bus companies are offering signing bonuses and attempting to lure employees from competitors to fill a critical shortage of drivers.

Ronna Weber, executive director of the National School Transportation Association, said that when the economy is strong and unemployment is low, potential drivers might balk at job qualifications, which include a commercial driver’s license, physical exam, drug test, background and driver’s history checks.

During the first weeks of classes, buses were two hours late at Beacon Academy Charter School in Maple Grove. Parents had to organize a carpool to get students home while teachers stayed after school to supervise student who were waiting for buses.

No buses arrived on the first day of school, said Doug Harrison, parent of two Beacon Academy students.

“Then we found out after the fact that there was this big issue,” Harrison said.

Beacon Academy Principal Sean Koster said things still weren’t back to normal a week after school started. The school has contracted with another company to have more buses showing up at dismissal time, the Star Tribune reported.

Troy Voigt’s School Bus Transportation in St. Cloud is offering a signing bonus of $500 as it looks to fill six more drivers to fill its routes.