; and (2) by adding at the end the following: (6) yardmaster employee means an individual responsible for supervising and coordinating the control of trains and engines operating within a rail yard. . (c) Conforming amendment The analysis for chapter 211 of title 49, United States Code, is amended by striking the item relating to section 21103 and inserting the following: 21103. Limitations on duty hours of train employees and yardmaster employees. . 6. Hazardous safety or security conditions (a) In general Section 20109(b) of title 49, United States Code, is amended by adding at the end the following: (4) A refusal to work described in paragraph (1)(B) may be an action by an individual employee, a group of employees, or a collective bargaining representative on behalf of affected employees. . (b) Enforcement Section 20109(d)(1) of title 49, United States Code, is amended by inserting , or a collective bargaining representative acting on behalf of affected employees, after An employee . 7. Excepted track and hazardous materials (a) Movements on excepted track Not more than 1 year after the date of enactment of this Act, the Secretary of Transportation shall update part 213.4(e) of title 49, Code of Federal Regulations, to make it clear that no railcar required to be placarded by the Federal Railroad Administration’s hazardous materials regulations shall be transported by a railroad on any segment of track defined by the Federal Railroad Administration as excepted track. (b) No waivers The Secretary may not waive or fail to enforce this limitation under any circumstances. 8. Track inspection requirements (a) Track inspection requirements Not more than 1 year after the date of enactment of this Act, the Secretary of Transportation shall update subpart F and subpart G, part 213 of title 49, Code of Federal Regulations, by requiring that a qualifying Track Geometry Measurement System (in this section referred to as TGMS ) operate over the following track classifications at the following frequencies: (1) For