My 40 plus year career in trucking included 25 years in safety management. Roadworthiness of trailers involved in Commercial Motor Vehicle (CMV) operation and Commercial Motor Carrier activities are governed by the Federal Motor Carrier Safety Administration (FMCSA). The design, construction, inspection, maintenance and repair of CMV trailers is clearly spelled out in the Federal Motor Carrier Safety Regulations (FMCSR). I am familiar with FMCSR related to trailer inspection, maintenance, and repair requirements of both the companies and the drivers. I have inspected trailers as a driver, as a driver trainer, and as a safety manager. Trailers that have defective equipment from a safety perspective are forbidden to be operated until repairs have been made that meet the requirements of the Federal Safety Regulations. The trucking company is required to follow FMCSR protocol and regularly inspect and maintain the equipment. Furthermore, the driver of the truck and trailer is required to perform a safety inspection every day before beginning his trip on the road. If defects are discovered, the vehicle is not to be moved. Federal regulations require minimum wheel and tire sizes as well as specified strength, number, and condition of lug nuts to securely fasten the wheel to the axle. Commercial vehicle law enforcement inspectors during roadside inspections regularly place out of service trucks or trailers with defective tires and wheels. Very importantly when a commercial motor vehicle experiences a breakdown on the highway, the driver is required to pull the truck and trailer completely off the highway onto the shoulder and immediately place warning devices behind the trailer to alert traffic of the vehicle breakdown.