State officials are warning those who rent limousines, motor coaches and party buses for special occasions to check that drivers are properly licensed and that their vehicles meet safety standards.

This after a recent saturation inspection of passenger-carrying vehicles used by students attending proms found 28 vehicles that were unsafe or driven by drivers who didn't have proper drivers licenses or certificates to do so.

The most egregious offense involved a driver who had only a Class D license and not a Class C license that's required operate a bus. That driver also didn't have a current physical on record and was operating without authority, said Becky Ellinghuysen, supervisor of safety and security operations in the Office of Freight and Commercial Vehicle Operations for the state.

That driver also was cited for having a defective lighting system and other safety violations. The driver and the bus were put out of service. Six minors on the bus also were cited for alcohol consumption, Ellinghuysen said.

The Minnesota Department of Transportation and the Minnesota State Patrol found the violations during inspections May 17 at the International Market Square in Minneapolis and the Mall of America in Bloomington.

Authorities also found buses, limousines and other passenger-carrying vehicles with safety violations ranging from defective parking brakes to inoperable horns and windshield wipers to radiator leaks. In some cases, drivers had inaccurate logs or had exceeded over their allotted driving hours.

"Our saturations ensure passenger transportation is being provided by authorized carriers using qualified drivers and safe vehicles," Ellinghuysen said

The Office of Freight and Commercial Vehicles Operations licenses and regulates more than 400 limousines and 350 passenger carriers in the state. Ellinghuysen said party buses are of particularly concern because they often are recycled school buses or transit buses and are typically not in good shape.

"Passenger transportation is being highly looked at due to accidents in states where people have been killed or injured," Ellinghuysen said. "We want people to contact us to verify the carrier has authority to operate, carries insurance and has a rating. As a customer, they should only book a trip with a company that has a satisfactory rating It's buyer beware before signing a contract."

To verify the status of a passenger carrier, call 651-215-6330.