49 C.F.R. § 218.93
As used in this subpart-
Clearance point means the location near a turnout beyond which it is unsafe for passage on an adjacent track(s). Where a person is permitted by a railroad's operating rules to ride the side of a car, a clearance point shall accommodate a person riding the side of a car.
Correspondence of crossover switches means both crossover switches are lined for the crossover or both are lined for the straight tracks.
Crossover means, for purposes of this subpart only, a track connection between two adjacent, but not necessarily parallel, tracks, consisting of two switches, which is intended to be used primarily for the purpose of crossing over from one track to another.
Departure track means a track located in a classification yard where rolling equipment is placed and made ready for an outgoing train movement.
Employee means an individual who is engaged or compensated by a railroad or by a contractor to a railroad to perform any of the duties defined in this subpart.
Foul or fouling a track means rolling equipment or on-track maintenance-of-way equipment is located such that the end of the equipment is between the clearance point and the switch points leading to the track on which the equipment is standing.
FRA means the Federal Railroad Administration.
Hand-operated switch means any type of switch when operated by manual manipulation. For purposes of this subpart, a hand-operated switch does not include switches operated by push button or radio control when such switch is protected by distant switch indicators, switch point indicators, or other visual or audio verification that the switch points are lined for the intended route and fit properly.
Highway-rail grade crossing means, for purposes of this subpart only, an at-grade crossing where a public highway, road, street, or private roadway, including associated sidewalks and pathways, crosses one or more railroad tracks at grade, and is identified by a U.S. DOT National Highway-Rail Grade Crossing Inventory Number, or is marked by crossbucks, stop signs, or other appropriate signage indicating the presence of an at-grade crossing.
Industry track means a switching track, or series of tracks, serving the needs of a commercial industry other than a railroad.
Locomotive means, for purposes of this subpart only, a piece of on-track equipment (other than specialized roadway maintenance equipment or a dual purpose vehicle operating in accordance with §240.104(a)(2) of this chapter):
Pedestrian crossing means a separate designated sidewalk or pathway where pedestrians, but not vehicles, cross railroad tracks. Sidewalk crossings contiguous with, or separate but adjacent to, highway-rail grade crossings, are presumed to be part of the highway-rail grade crossings and are not considered pedestrian crossings.
Qualified means that a person has successfully completed all instruction, training, and examination programs required by the railroad and this subpart and that the person, therefore, has actual knowledge or may reasonably be expected to have knowledge of the subject on which the person is expected to be competent.
Remote control operator means a locomotive engineer, as defined in §240.7 of this chapter, certified by a railroad to operate remote control locomotives pursuant to §240.107 of this chapter.
Remote control zone means one or more tracks within defined limits designated in the timetable special instructions, or other railroad publication, within which remote control locomotives, under certain circumstances specified in this part, may be operated without an employee assigned to protect the pull-out end of the remote control movement, i.e., the end on which the locomotive is located.
Roadway maintenance activity means any work limited to the duties prescribed for a roadway worker by definition in this section, including movement of on-track maintenance-of-way equipment other than locomotives.
Roadway worker means any employee of a railroad, or of a contractor to a railroad, whose duties include inspection, construction, maintenance or repair of railroad track, bridges, roadway, signal and communication systems, electric traction systems, roadway facilities or roadway maintenance machinery on or near track or with the potential of fouling a track, and flagmen and watchmen/lookouts as defined in §214.7 of this chapter.
Roadway worker in charge means a roadway worker who is qualified in accordance with §214.353 of this chapter for the purpose of establishing on-track safety for roadway work groups.
Siding means an auxiliary track, adjacent and connected to a main track, used for meeting or passing trains.
Signaled siding means a siding within traffic control system (TCS) territory or within interlocking limits where a signal indication authorizes the siding's use.
Switchtender means a qualified employee assigned to handle switches at a specific location.
Track is clear means:
Yard access crossing means a private highway-rail grade crossing that is located within the physical confines of a railroad yard and is either:
49 C.F.R. §218.93