12. Warning System Operation - General

12.0 Except as otherwise specified in articles 12 to 16 and Appendix B of these Standards or in the Grade Crossings Regulations, warning systems must be in accordance with the requirements and recommended practices of Part 3 of the AREMA Communications and Signals Manual (cited in Part A).  

12.01 For the purposes of these Standards, the following interpretations and adjustments apply with respect to AREMA: 

  1. Any guidelines, recommendations, and similar matters are to be considered mandatory;
  2. Any references to "should" are to be read as "must";
  3. The term "highway-rail grade crossing warning system" is to be read as "warning system";
  4. The term "railroad" and the phrase "operators of the passenger or commuter rail system" is to be read as "railway company";
  5. The term "lights" is to be read as "light units";
  6. The term "train" is to be read as "railway equipment";
  7. The term "roadway" and "roadway approach" is to be read as "road approach";
  8. All references to the "MUTCD" are to be disregarded;
  9. All "Purpose" articles, paragraph 2 of article  3.1.16 G.1.(b)(ii) and article  3.2.35 K 5, are to be disregarded;
  10. The following are to be disregarded:
    1. all references to and requirements related to the "Diagnostic Team";
    2. all references to and requirements related to the "highway agency" or "highway agency or authority with jurisdiction";
    3. all references to and requirements related to the "agency" or "public agency";
    4. all references to and requirements related to "manufacturers" except where the requirement is to do something in accordance with the manufacturer's instructions;
    5. all references to "unless otherwise specified" or "other considerations", all references to approvals or orders, and any other reference to the exercise of discretion;
    6. all purchase order requirements;
    7. all requirements to create or keep records;
    8. all requirements for a diagnostic review, an engineering study, a study of train operations, a risk analysis, a safety analysis, and all requirements to provide special instructions, operating rules, orders, or operational procedures.

12.1  Signal assemblies must be as shown in Figure 12-1, and gate assemblies must be as shown in Figure 12-2 and the cantilever assembly's clearance must be as shown in Figure 12-3, and must meet the following specifications:

  1. The minimum clearance distance from the face of a curb to the clearance line must be 625 mm (2 ft);
  2. Where there is no curb, the minimum clearance distance must be 1.875 m (6ft) from the edge of the travelled way to the clearance line and a minimum of 625 mm (2 ft) from the outer edge of the road approach shoulder to the clearance line, if there is a shoulder;
  3. The top of the warning signal foundation must be at a minimum of 100 mm (4 inches) above the surrounding ground.  The slope of the surrounding ground away from the foundation toward the travelled way must not exceed the ratio of 4:1;

  4. The gate arm reflective materials shall have:
    1. stripes of 406 mm (16 inches), and must be affixed with white and red alternately and be aligned vertically;
    2. Retroreflective material must meet the specifications for Type XI, white sheeting, in sections 4 and 6 of ASTM D4956 (cited in Part A), when tested in accordance with the Test Methods for Type XI specified in sections 7 and 9 of that Standard; and
    3. The retroreflection coefficient of the retroreflective material referred to in (ii) is to be maintained above 50 per cent of the value specified for Type XI, white sheeting, in sections 4 and 6 of ASTM D4956 (cited in Part A).

  5. For grade crossings used by vehicles, gate arms must extend to within 1 m (3 ft) of the farthest edge of that portion of the road approach. Where gates are installed on each side of the same road approach, gate ends must extend to within 1 m (3 ft) of each other.
  6. Where gates are installed at sidewalks, paths or trails:
    1. Each gate arm must extend across the full width of the sidewalk, path or trail; and
    2. in the case of a sidewalk, path or trail that is less than 3.5 m (11.5 ft.) wide, two lights are required on each gate arm located so that the lights are over the two points dividing the sidewalk, path or trail into thirds. The two gate arm lights must flash alternately.
  7. the height of the cantilever assembly clearance must be between 5.2 m (17 ft) and 6.0 m (20ft) above the crown of the road as shown in Figure 12-3.

12.2  In addition, warning systems must have monitoring devices that gather and retain the date and time of the following information for a minimum of 30 days;

  1. Activation and deactivation of Interconnected devices;
  2. Gates have returned to or left the vertical position (Gate up Position);
  3. Gates have descended to a point 10 degrees from horizontal (Gate down Position);
  4. Activation of the warning system test switch
  5. Activation and deactivation of all track circuits used in the control of the warning system, including electronic track circuits;
  6. Activation of the warning system;
  7. Activation and deactivation of all devices used to control the warning systems at adjacent crossings; and
  8. Activation and deactivation of all devices used to activate the warning system from a location other than the crossing.

12.3  All control circuits that affect the safe operation of a warning system must operate in a manner that activates the warning system if there is a failure of a safety-critical component of that system.

12.4  The electromagnetic, electronic, or electrical apparatus of a warning system must be operated and maintained in accordance with the limits to which the system is designed to operate.

12.5  Railway track circuits must:

  1. detect railway equipment in any part of the track circuit;
  2. detect a shunt of 0.06 ohm resistance when the shunt is connected across the track rails of any part of the circuit;
  3. provide a set of fouling wires that consist of at least two discrete conductors and must ensure proper operation of the track circuit when the circuit is shunted. Single duplex wire with single plug is not permitted;
  4. in the case of a non-insulated rail joint within the limits of a track circuit, be bonded by means other than joint bars and the bonds must ensure electrical conductivity; and
  5. in the case of an insulated rail joint used to separate track circuits, prevent current from flowing between rails separated by the insulation.

12.6  Warning system battery back-up of 8 hours of continuous activation and 24 hours of normal railway operations must be provided.

Figure 12-1 – Warning Signal Assemblies

Text version for Figure 12-1

Figure 12-2 – Gates

Text version for Figure 12-2

Figure 12-3 – Cantilevers

Text version for Figure 12-3

Date modified: