Safety Regulations
This domain tests the regulatory rules that apply to commercial drivers: seat belts, distracted driving, impairment, out-of-service orders, inspections, and medical certification. The exam rewards precise thresholds.
Key rules
Wear a seat belt whenever the vehicle is moving. Texting and handheld phone use are prohibited while driving; Indiana has a hands-free law, and federal rules prohibit texting and handheld use in CMVs. The CMV alcohol limit is 0.04 BAC-lower than the 0.08 limit for non-commercial drivers. An out-of-service order must be complied with; driving while out of service can lead to disqualification. Carry a current medical examiner's certificate if required, and complete inspection reports.
Worked example
A driver with a CDL is stopped with a 0.05 BAC. That is below the 0.08 limit for a non-commercial driver, but it exceeds the 0.04 CMV limit, so it is a violation and can lead to disqualification. The same applies to handheld phone use: a short call at a light can still violate the hands-free rule. Do not assume the non-commercial threshold applies just because the vehicle is not loaded.
Traps that cost marks
Using 0.08 as the CMV limit; assuming a hands-free law allows holding a phone at a stop; ignoring an out-of-service order; and letting a medical certificate expire. Also do not treat a traffic violation in a personal vehicle as irrelevant to CDL status.