; (2) to alter the terms or interpretations of existing collective bargaining agreements; or (3) to abridge any procedural rights or remedies provided under a collectively bargained agreement. 15. Rail safety inspections GS classification adjustment (a) GS classification adjustment Subsection (b) of Section 5109 of Title 5, United States Code is amended by— (1) In paragraph (1), striking GS–12 and inserting GS–13 ; and (2) In paragraph (2), striking GS–13 and inserting GS–14 . (b) Office of personnel management corresponding actions Not later than 180 days after the date of enactment of this Act, the Director of the Office of Personnel Management shall update the Railroad Safety Series, GS–2121, TS–37 dated November 1979, to reflect the amendment made in subsection (a). (c) Secretary of transportation corresponding actions Not later than 180 days after the date of enactment of this Act, the Secretary of Transportation shall update the Railroad Safety Inspector and Railroad Safety Specialist General Schedule grades, to reflect the amendment made in subsection (a). 16. Minimum amount of federal rail safety inspectors (a) In general Subchapter II of chapter 201 of title 49, United States Code, is further amended by adding at the end the following: 20176. Rail safety inspectors (a) Minimum rail inspector level The Office of Safety of the Federal Railroad Administration shall have not less than 425 railroad safety inspectors, as described in section 5109(b)(1) of title 5. (b) Breakdown Of the railroad safety inspectors required under subsection (a), there shall be at least— (1) 80 that are hazardous materials experts; (2) 80 that are track experts; (3) 80 that are motive power and equipment experts; (4) 80 that are signals and train control experts; (5) 80 that are operating practice experts