The paperwork starts before the first trip. Under § 391.21, a person shall not drive a commercial motor vehicle unless they have completed and furnished the employing carrier an application for employment meeting the section’s requirements. The form is furnished by the carrier, must be completed and signed by the applicant, and must contain the information § 391.21(b) enumerates — beginning with the name and address of the employing carrier and running through the applicant’s driving and employment history. The obligation runs to the DRIVER: an incomplete application is a reason the driver may not drive, not merely a gap in the carrier’s records.

§ 391.23 then requires the carrier to go and check. Two investigations, on two different clocks, and both reach backwards three years. The first is an inquiry, within 30 days of the date the driver’s employment begins, to each driver licensing authority where the driver held a license or permit during the preceding 3 years, to obtain that driver’s motor vehicle record covering the prior 3-year driving history. The second is an investigation of the driver’s safety performance history with Department of Transportation regulated employers during the preceding three years.

The distinction between them is worth holding. The first asks the States what your driving record says; the second asks your previous DOT-regulated employers what your safety history with them was. They come from different sources and they can disagree, which is precisely why the rule requires both rather than treating either as sufficient. Note too that the 30-day window runs from the start of employment, not from the offer — a carrier may lawfully put a driver to work before the record arrives, and often does.