This part applies to all railroad freight cars and locomotives that operate over a public or private highway-rail grade crossing and are used for revenue or work train service, except:
- (a) Freight rolling stock that operates only on track inside an installation that is not part of the general railroad system of transportation;
- (b) Rapid transit operations in an urban area that are not connected to the general railroad system of transportation;
- (c) Locomotives and passenger cars used exclusively in passenger service; or
- (d) Freight rolling stock that is subject to a reflectorization requirement promulgated by another Federal agency.