49 U.S.C. § 20504 — Inspection, testing, and investigation

(a) Inspecting systems already in use. (1) The Secretary of Transportation may (A) inspect and test a signal system a railroad is using, and (B) decide whether it's in safe operating condition. (2) To do this, the Secretary can only use an inspector who (A) has no financial interest in any patented part required for the signal system, and (B) has no financial interest in a railroad carrier or in any business selling railroad supplies. (b) Testing systems submitted voluntarily. The Secretary may investigate, test, and report on how useful and needed a signal system is, at no cost to the government, when someone submits the finished system for that investigation and testing.