49 U.S.C. § 20305
Inspection of mail cars
The Secretary of Transportation shall inspect the construction, adaptability, design, and condition of mail cars used on railroads in the United States. The Secretary shall make a report on the inspection and submit a copy of the report to the United States Postal Service.
( Pub. L. 103–272, § 1(e) , July 5, 1994 , 108 Stat. 883 .)