Motor Carrier Safety Assistance Program (MCSAP) inspectors conduct roadside inspections to ensure compliance with the Federal Motor Carrier Safety Regulations and Hazardous Materials Regulations. If an inspection results in a serious violation, the driver is issued an out-of-service (OOS) order. These violations must be corrected before the driver or vehicle can return to service. The FMCSA keeps a close eye on the most common vehicle violations. This data can be used to maintain a safe fleet and keep businesses in compliance with the rules of the road. Here are the 10 most common OOS orders issued for vehicle and driver violations during the 2022 fiscal year.