49 CFR 383.37 : Transportation (§ 1.1 To Parts 1581-1699) — (Parts 300-302 To Appendix G To Subchapter B Of Chapter Iii) — Other Regulations Relating To Transportation (Continued) (Parts 300-302 To Appendix G To Subchapter B Of Chapter Iii) — Federal Motor Carrier Safety Administration, Department Of Transportation (Parts 300-302 To Appendix G To Subchapter B Of Chapter Iii) — Federal Motor Carrier Safety Regulations (§ 350.101 To Appendix G To Subchapter B Of Chapter Iii) — Commercial Driver'S License Standards; Requirements And Penalties (§ 383.1 To § 383.155) — Notification Requirements And Employer Responsibilities (§ 383.31 To § 383.37) — Employer responsibilities.

No employer may allow, require, permit, or authorize a driver to operate a CMV in the United States if he or she knows or should reasonably know that any of the following circumstances exist:

(a) During any period in which the driver does not have a current CLP or CDL or does not have a CLP or CDL with the proper class or endorsements. An employer may not use a driver to operate a CMV who violates any restriction on the driver's CLP or CDL.

(b) During any period in which the driver has a CLP or CDL disqualified by a State, has lost the right to operate a CMV in a State, or has been disqualified from operating a CMV.

(c) During any period in which the driver has more than one CLP or CDL.

(d) During any period in which the driver, or the CMV he/she is driving, or the motor carrier operation, is subject to an out-of-service order.

(e) In violation of a Federal, State, or local law or regulation pertaining to railroad-highway grade crossings.