49 U.S. Code § 31143. Investigating complaints and protecting complainants
The Secretary of Transportation shall conduct a timely investigation of a nonfrivolous written complaint alleging that a substantial violation of a regulation prescribed under this subchapter is occurring or has occurred within the prior 60 days. The Secretary shall give the complainant timely notice of the findings of the investigation. The Secretary is not required to conduct separate investigations of duplicative complaints.
Notwithstanding section 552 of title 5, the Secretary may disclose the identity of a complainant only if disclosure is necessary to prosecute a violation. If disclosure becomes necessary, the Secretary shall take every practical means within the Secretary’s authority to ensure that the complainant is not subject to harassment, intimidation, disciplinary action, discrimination, or financial loss because of the disclosure.
Telephone Hotline for Reporting Safety Violations
For a period of not less than 2 years beginning on or before the 90th day following the date of enactment of this Act [June 9, 1998], the Secretary [of Transportation] shall establish, maintain, and promote the use of a nationwide toll-free telephone system to be used by drivers of commercial motor vehicles and others to report potential violations of Federal motor carrier safety regulations.
The Secretary shall monitor reports received by the telephone system and may consider nonfrivolous information provided by such reports in setting priorities for motor carrier safety audits and other enforcement activities.
The toll-free telephone system shall be staffed 24 hours a day 7 days a week by individuals knowledgeable about Federal motor carrier safety regulations and procedures.
“(d) Protection of Persons Reporting Violations.—