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FHWA Home / Safety / HSIP / Recording Devices for Interconnected Grade Crossing and Intersection Signal System

Recording Devices for Interconnected Grade Crossing and Intersection Signal Systems: An Informational Report

Appendix D: Highway Signal Preventative Maintenance Checklist

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The following is a summary of the monthly, quarterly and annual requirements for inspection and testing at highway-rail grade crossings and the current standard inspection and testing practices from the railroad industry as a whole.

Warning System Operation

Monthly Tests

The 49 CFR regulations explain in detail the method by which the railroad carrier must warn the public of an oncoming train at an active at-grade crossing. Active crossings are crossings that have automatic flashing lights, bell and gates as well as any other active warning device which may support the Automatic Highway Warning System (AHWS).

Currently, every AHWS system in the country is tested monthly by the railroad carrier as defined by CFR Rule 234.257 - Warning System Operation:

(a) Each highway-rail crossing warning system shall be tested to determine that it functions as intended when it is placed in service. Thereafter, it shall be tested at least once each month and whenever modified or disarranged.

(b) Warning bells or other stationary audible warning devices shall be tested when installed to determine that they function as intended. Thereafter, they shall be tested at least once each month and whenever modified or disarranged.

Railroad testing procedures generally direct inspecting personnel to ensure that warning system equipment is visible and audible to highway users approaching the crossing and that they operate together with the flashers.

Quarterly Tests

The 49 CFR also defines inspections at highway-rail grade crossings that must be completed at least once every 3 months or quarterly:

CFR Rule 234.269 - Cut-out circuits, railroads must test any cut-out circuits at least once every three months to determine that the circuit functions as intended. These are usually tests of specialty circuits used to bypass or override the operation of the automatic warning systems, or in some cases even preempt or activate the crossing warning system.

CFR Rule 234.271 requires the inspection of insulated rail joints, bond wires, and track connections, at least once every three months. These tests are used to assure that trains are being properly detected on each of the railroad approaches.

Annual Tests

In addition to the monthly and quarterly testing, a complete test of the grade crossing occurs once every year. The annual inspection is normally performed by different personnel from those that perform the monthly and quarterly tests. Several components of highway-rail grade crossing warning systems that are not required to be tested in the monthly or quarterly inspections must be inspected in the annual inspection. These tests include those for flashing light alignment and flash rate, lamp voltage, hold clear devices and timing relays.

CFR Rule 234.265 requires that timing relays and timing devices are tested at least once every twelve months. Railroad testing procedures instruct inspection personnel to observe the time delay of starting circuits and cut-out circuits and check that they are between 90 and 110 percent of the predetermined time interval shown on the plans.

CFR Rule 234.263 - Relays, defines the required inspections and the inspection frequency for different types of relays associated with the grade crossing warning system. Railroad testing procedures generally instruct inspecting personnel to check relay operation for each track and in each direction and to ensure that the relays are de-energized after testing is complete. Some railroads provide specific instructions for inspection of each relay type and for testing with current and voltage.

Warning Time

CFR Rule 234.225 - Activation of warning system, states:

A highway-rail grade crossing warning system shall be maintained to activate in accordance with the design of the warning system, but in no event shall it provide less than 20 seconds warning time for the normal operation of through trains before the grade crossing is occupied by rail traffic.

Once every 12 months, railroads are required to test the prescribed crossing warning time as stated in the CFR, Rule 234.259 - Warning time:

Each crossing warning system shall be tested for the prescribed warning time at least once every 12 months and when the warning system is modified because of a change in train speeds.

Railroads' testing procedures generally describe the purpose of this as to ensure the grade crossing warning system activates as it is designed to, and in no event provides less than 20 seconds of warning time.

Inspection personnel are instructed to observe the crossing warning time and verify that it is in accordance with the designed warning system as shown on the circuit drawings.

If the crossing is equipped with an electronic recording device that accurately records warning times, it may be used to perform the test. If no such device is installed, the warning time must be found by observing a train movement or calculating the warning time by measuring the approach track circuits and using the highest timetable speed.

If the warning time is found to be less than 20 seconds, inspecting personnel are directed to immediately take corrective action. Corrective action must also be taken if the warning time is consistently found to be less than the designed warning time.

Highway Traffic Signal Preemption

The required inspection of highway traffic preemption is defined in CFR Rule 234.261 - Highway traffic signal pre-emption:

Highway traffic signal pre-emption interconnections, for which a railroad has maintenance responsibility, shall be tested at least once each month.

The majority of railroad testing procedures identify the test frequency for highway traffic signal preemption as when the traffic preemption system is placed in service, is modified or disarranged, and at least once per month. Railroad test procedures also typically state that the railroad is only responsible for maintenance and testing up to the point of interconnection with the highway traffic control system, and that the local authority is responsible for maintenance and testing of all remaining circuitry and traffic signal control devices.

The test purpose generally described is to ensure that an approaching train activates the crossing warning devices and highway traffic signals and that they are operating properly.

Railroads' testing procedures generally instruct testing personnel to check contacts and devices interconnected with the highway traffic signals and advanced warning signs to ensure they perform as intended.

Inspection personnel are also instructed to verify the proper operation of the interconnect circuit and to observe the traffic preemption is operating as it is intended. Some railroads specify that this can be done by observing a train movement and verifying that the warning signs and traffic signal preemption are activated. If observing a train movement is not possible, inspecting personnel must simulate a train movement by de-energizing the interconnection circuit thereby activating the preemption sequence. If the crossing is equipped with advanced preemption, some railroad testing procedures require inspection personnel to observe a train movement to verify proper operation.

Inspection personnel are instructed to note any repairs or adjustments made during the inspection. If the interconnection circuit is discovered to be not operational and/or any inconsistency is discovered, inspection personnel are instructed to notify the local roadway authority and report it to their supervisor. If the railroad equipment is found to be operating properly and the traffic signal system does not respond, inspection personnel are instructed to notify the local roadway authority of the problem.

Some railroads state that it may be necessary to have a local highway authority representative present to assist with tests and perform maintenance and repairs if necessary. A few states have developed detailed joint inspection procedures for highway-rail grade crossings equipped with traffic preemption.


Page last modified on October 15, 2014
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