Technical Resources

Notice of Intent to Consider for Final Adoption - Preemption of Traffic Signals Near Railroad Crossings Recommended Practice, Second Edition

Notice of Intent to Consider for Final Adoption as an ITE Recommended Practice


The recommended practice Preemption of Traffic Signals Near Railroad Crossings (RP-025D) is now available. A version of the full report will be available for review by request by sending an email to


The final version of Preemption of Traffic Signals Near Railroad Crossings (RP-025D) is moving for final adoption by the ITE International Board of Direction. ITE made the recommended practice available on December 23, 2020 for review and will submit the recommended practice for adoption as of January 23, 2021 if no appeals are received. In response to the comments received on the proposed version of the document, the report has been revised to:

  • Modify the approach for passive crossing evaluation;

  • Expand discussion of simultaneous versus advance preemption operation;

  • Clarify aspects of upstream versus downstream pre-signal location, and the use of pre-signals and overhead flashing-light signals;

  • Expand discussion of advance pedestrian  preemption;

  • Supplement discussion on the maximum preemption timer;

  • Modify text regarding motion-sensing detection circuits;

  • Clarify interconnection types relative to current standards;

  • Modify definitions of certain terms and their use in the report, including terms such as right-of-way; right-of-way transfer time; and constant warning time to be consistent with other relevant recently adopted practice;

  • Emphasize the role of the railroad signal engineer on the diagnostic team; and

  • Include updated figures as well as other technical and editorial revisions to improve readability and clarity.

During the first notice period which closed on April 30, 2020, ITE received three appeals regarding report content. In response to the comments received, the report has been revised to:

  • Add resources from NCHRP Report 812, Signal Timing Manual, 2nd Edition and NCHRP Synthesis 507, Traffic Signal Preemption at Intersections Near Highway-Rail Grade Crossings;

  • Modify discussion and guidance related to pedestrian timing;

  • Supplemented guidance related to preemption operations modes of simultaneous and advance preemption operation;

  • Expand discussion of dynamic strategies for right of way transfer time variability;

  • Supplemented text regarding prescribed warning time and maximum preemption timing parameters;

  • Clarify certain definitions; and Include other technical and editorial revisions to improve readability and clarity of the report.

Purpose and Intended Use

Where a signalized intersection exists in close proximity to a railroad crossing—and either queues from the intersection impact the crossing, or queues from the crossing impact the inter- section—the railroad signal control equipment and the highway traffic signal control equipment should be interconnected. The normal operation of the traffic signals controlling the intersection should be preempted to operate in a special control mode when trains are approaching. While public agencies have practices or procedures on the preemption of traffic signals near railroad grade crossings, there have been significant advances in engineering and technology since the last edition in 2006. The goal of the recommended practice is to reflect the current state-of-

the-practice and to provide the user with a broad overview of key considerations. The report is written primarily for engineers working for public agencies, railroads, and public transit agencies engaged in signal design and operational timing. ITE’s intent for the recommended practice is to reflect a balance between sound engineering theory and practical application.

The Recommended Practice

The report includes new information on the design and operation of traffic signal preemption that has been developed since the previous edition was published, including:

  • The concept and the function of diagnostic teams.

  • Explanation of the critical factor for determining the need for preemption is not the distance to the crossing, but the likelihood that a traffic queue will extend onto the tracks, regardless of distance. Additional methods for estimating queue lengths are provided.

  • New definitions have been added as well as new drawings illustrating the definitions of the Clear Storage Distance and the Minimum Track Clearance Distance.

  • Illustrated explanation of the procedure for preempting traffic signals of diagonal crossings at intersections.

  • Illustrated discussion of the use of pavement markings to warn drivers of the area of a railroad crossing to not block.

  • Discussion of Americans with Disabilities Act (ADA) considerations.

  • Additional discussion on the need for special traffic control when there is construction in the vicinity of a railroad crossing, consistent with the requirements of the Manual on Uniform Traffic Control Devices.

  • Detailed information regarding the use of pre-signals and queue-cutter signals as well as hybrid systems for long distances between the traffic signal and the railroad crossing.

  • Expansion of the section on the design of preemption interconnection  circuits.

  • Supplemental information regarding the timing of traffic signal preemption to accommodate pedestrians.

  • New information regarding the need for preemption of flashing beacons or hybrid beacons at pedestrian crossings.

  • References to preemption timing worksheets from two roadway jurisdictions as methodological examples.

The development of the recommended practice was coordinated with the Highway-Rail Crossing Handbook, 3rd Edition, so that the information will be consistent in both documents.

How to File an Appeal

If you wish to appeal ITE’s adoption of the recommended practice, submit a written appeal to ITE Headquarters, Attn: Douglas E. Noble, 1627 Eye Street, NW, Suite 600, Washington, DC 20006 USA, by the close of business on January 23, 2021. The written appeal shall state the nature of the objection(s) including any adverse effects, the step(s) of the ITE procedures or the section(s) of the recommended practice that are at issue and the specific remedial action(s) that would satisfy the appellant’s concerns. Any previous efforts to resolve the objection(s) and the outcome of each shall also be noted.