Each motor carrier and intermodal equipment provider must systematically inspect, repair, and maintain all commercial motor vehicles (CMVs) under its control. Every employee of a carrier that is directly involved with the inspection and upkeep of vehicles must comply with the rules and regulations of 49 CFR 396.
Parts and accessories shall be in safe and proper operating condition at all times. These include those specified in 49 CFR 393 and any additional parts and accessories that may affect safety of operation, including but not limited to, frame and frame assemblies, suspension systems, axles and attaching parts, wheels and rims, and steering systems. Pushout windows, emergency doors, and emergency door marking lights in buses shall be inspected at least every 90 days.