Md. Code, Transportation § 18.5–105

A person may not allow a shared vehicle driver, or any other individual who will drive a shared motor vehicle, to operate the shared motor vehicle if the person knows that the shared vehicle driver, or other individual, is under the influence of alcohol, impaired by alcohol, impaired by a drug, a combination of drugs, or a combination of one or more drugs and alcohol, or impaired by a controlled dangerous substance.