and/or transports placardable amounts of hazardous materials by ground in any vehicle on a public road while in commerce, may be subject to additional Federal Motor Carrier Safety Regulations including: Driver Qualification Files, Medical Certification (obtained before onboarding), Road Test, Hours of Service, Drug and Alcohol Testing, vehicle inspection requirements, CDL requirements (if applicable) and hazardous materials transportation/shipping training. lib models for custom digital and analog-digital interface circuits: Define and characterize timing arcs including input-to-output delay, clock-to-Q delay, setup and hold constraints, recovery and removal timing, minimum pulse-width constraints, enable/disable timing, tristate or conditional timing arcs, where applicable.