Note: This document summarizes current practices but does not set standards; practitioners are advised to check current local standards and requirements (refer to Disclaimer and Quality Assurance Statement). Users of the data provided within this document should anticipate possible variations from current information within the FRA databases, which are updated monthly.
The Highway-Rail Crossing Handbook Third Edition (Handbook) is a compendium of recommended safety engineering treatments for at-grade highway-rail crossings (crossings) which summarizes current noteworthy or best practices and provides a range of options for consideration. It is an information resource to provide a unified reference document on prevalent and best practices as well as adopted standards relative to highway-rail grade crossings. The purpose of the Handbook is not to establish standards, but to provide guidance about how existing standards and recommended practices may be applied in developing safe and effective treatments for crossings. For this purpose, the Railroad-Highway Grade Crossing Handbook, Revised Second Edition, August 2007, has been updated and re-organized to showcase noteworthy practices regarding device selection, while retaining relevant background information.
The Handbook is intended for use by practitioners of all levels of knowledge and experience involved with the design and management of highway-rail crossings. This includes: local highway agencies/authorities, municipal planners, traffic engineers, transportation planners, safety analysts, Metropolitan Planning Organizations (MPOs), State Departments of Transportation (DOT), and allied regulatory commissions (including people responsible for program development, safety management, and data management sections of the applicable State agency), railroad public project managers, public safety coordinators, railroad maintenance officials, and signal designers and maintainers, law enforcement agencies and emergency responders. Additionally, non-governmental advocates and organizations such as Operation Lifesaver, Inc.'s Authorized Volunteers, school transportation managers, commercial motor carriers, property developers and others may also benefit from sections of the Handbook.
This edition of the Handbook is intended to be consistent with the 2009 edition of the Manual on Uniform Traffic Control Devices (MUTCD).(1) Guidance in general use by practitioners within the industry that is not prescribed within the MUTCD has been characterized as "current practice." If there are differences between this Handbook and the current edition of the MUTCD, then the MUTCD, Interim Approvals, and Interpretations should be followed.
The Handbook is consistent with the 2013 version of the Traffic Control Devices Handbook prepared by the Institute of Transportation Engineers (ITE) and also incorporates portions of the Proposed Recommended Practice for Preemption of Traffic Signals Near Railroad Crossings, which was updated in 2019 by ITE.(2,3)
Additionally, the Handbook provides an update to and supersedes the Guidance on Traffic Control Devices at Highway-Rail Grade Crossings originally developed in 2002 by the United States Department of Transportation (USDOT) Federal Highway Administration (FHWA) Highway/Rail Grade Crossing Technical Working Group (TWG). This update was accomplished by a task force of knowledgeable practitioners conversant with current best practices and as such the guidance provided in this Handbook supersedes the prior version.
Abandonment. The relinquishment of interest (public or private) in a ROW or activity thereon with no intention to reclaim or use again for the original purposes.
Active Crossing. A grade crossing which includes an Active Grade Crossing Warning System as described below.
Active Grade Crossing Warning System. The flashing-light signals, with or without warning gates, together with the necessary control equipment used to inform road users of the approach or presence of rail traffic at grade crossings.
Advance Preemption. The notification of approaching rail traffic that is forwarded to the highway traffic signal controller unit or assembly by the railroad equipment in advance of the activation of crossing warning devices.
Advance Preemption Time. The period of time that is the difference between the required maximum highway traffic signal preemption time and the activation of the railroad warning devices.
Alignment, Exclusive ("exclusive alignment"). The LRT track(s) or a busway alignment that is grade-separated or protected by a fence or traffic barrier. Motor vehicles, pedestrians, and bicycles are prohibited within the traveled way. Subways and aerial structures are included with this group.
Alignment, Mixed-Use ("mixed-use alignment"). An alignment where the LRT vehicles or buses operate in mixed traffic with all types of road users. This includes streets, transit malls, and pedestrian malls where the traveled way is shared. In a mixed-use alignment, the LRT vehicles or buses do not have right-of-way over other roadway users at crossings and intersections.
Alignment, Semi-Exclusive ("semi-exclusive alignment"). The LRT track(s) or a busway alignment that is in a separate traveled way or along a street or railroad ROW where motor vehicles, pedestrians, and bicycles have limited access and cross at designated locations only. In a semi-exclusive alignment, the LRT vehicles or buses usually have ROW over other roadway users at crossings.
Americans with Disabilities Act (ADA) of 1990. A civil rights law that prohibits discrimination based on disability. Refers to the ADA of 1990 (PL 101-336) and the ADA Amendments Act of 2008 (PL 110-325).
Anchors. Rail-fastening devices used to resist the longitudinal movement of rail due to train operations and maintain proper expansion allowance for temperature changes at joint gaps.
Annual Average Daily Traffic (AADT). The total volume of traffic passing a point or segment of a highway facility in both directions for one year divided by the number of days in the year. Normally, periodic daily traffic volumes are adjusted for hours of the day counted, days of the week, and seasons of the year to arrive at average annual daily traffic.
Apportionment. An administrative distribution of funds based on a prescribed formula provided in law by a governmental unit to another governmental unit for specific purposes and for certain periods.
Appropriation. The act of a legislative body that makes federal-aid highway funding available for obligation and expenditure with specific limitations as to amount, purpose, and duration.
Ballast. Material placed on a track roadbed to hold the track in alignment and elevation. It consists of crushed stone, generally 1 to 2 inches in size, angular, rough-surfaced, clean and free of sand, loam, clay, flat, elongated, soft or disintegrated pieces, and other deleterious substances.
Bar Signals (LRT). An illuminated signal configured in the shape of a bar, normally positioned to appear in a vertical, angled, or horizontal orientation. These are used as aspects to convey a signal indication. Bar signals are typically used on LRT systems. LRT bar signals are white, monochrome bar signals that are separated in space from motor vehicle signals.
Barrier Gate (Barrier Gate Arm, Warning/Barrier Gate, Vehicle Arresting System). An automatic gate of specialized design, which can be used as adjunct to flashing light signals to provide positive closure by blocking approaching traffic at a highway-rail crossing and preventing vehicle penetration.
Benefit-Cost Ratio. The economic value of the project benefits (e.g., reduction in fatalities, injuries, and property damage, reduced delay, reduced fuel and operating costs, reduction in emissions, etc.) divided by the cost of the project.(4)
Blank-Out Sign. A sign that displays a single predetermined indication only when activated. When not activated, the sign legend should not be visible.
Cantilevered Signal Structure (Cantilever). A structure that is rigidly attached to a vertical pole and used to provide overhead support of signal units; the term Cantilever refers to a Cantilevered Signal Structure with one or more flashing-light units attached.
Channelization Device. A traffic separation system made up of a raised longitudinal channelizer with vertical panels or tubular delineators. These devices can serve several purposes such as being placed between opposing highway lanes designated to alert or guide traffic in a particular direction, or as a fencing system used to separate modes (e.g., channelize pedestrians).
Clear Storage Distance. The distance available for vehicle storage measured between six (6) feet from the rail nearest the intersection to the intersection stop line or the normal stopping point on the highway.
Clearing Sight Distance. The distance measured along the track which a road user must be able to see to decide whether it is safe to cross based upon the speed of an approaching train and the acceleration characteristics of the highway vehicle.
Clear Zone. The total roadside border area, starting at the edge of the traveled way, available for safe use by errant vehicles. This area may consist of a shoulder, a recoverable slope, a non-recoverable slope, and/or a clear run-out area.
Constant Warning Time Detection. A means of detecting rail traffic that provides road users with relatively uniform warning times prior to the approach of through trains that neither accelerate nor decelerate after having been detected.
Crossing Angle. The angle 90 degrees or less between the intersection of the centerlines of the railroad tracks and the roadway.
Design Vehicle. The longest vehicle permitted by statute of the road authority (State or other) on that roadway.
Diagnostic Team. A group of knowledgeable representatives of the parties of interest (such as the railroad, road authority, State regulatory agency, where applicable) in a highway-rail crossing or group of crossings who evaluate conditions at the crossing(s) to identify safety issues.
Dynamic Envelope. The clearance required for the train and its cargo overhang due to any combination of loading, lateral motion, or suspension failure.
Dynamic Exit Gate Operating Mode. A mode of operation where the exit gate operation is based on the presence of vehicles within the minimum track clearance distance.
Easement. A right to use or control the property of another for a designated purpose. Examples include:
- Drainage easement. An easement for directing the flow of water.
- Planting easement. An easement for reshaping roadside areas and establishing, maintaining, and controlling plant growth thereon.
- Sight line easement. An easement for maintaining or improving the sight distance.
- Slope easement. An easement for cuts or fills.
Economic Analysis. A determination of the cost-effectiveness of a project by comparing the benefits derived and the costs incurred in a project.
Entrance Gate. An automatic gate that can be lowered across the lanes approaching a grade crossing to block road users from entering the grade crossing.
Exit Gate. A crossing gate that is used on the departing lanes of traffic to block users from entering a highway rail crossing.
Exit Gate Clearance Time. For four-quadrant gate systems, the amount of time provided to delay the descent of the exit gate arm(s) after entrance gate arm(s) begin to descend.
Exit Gate Management System. A system using a detector or detectors with processing logic to identify the presence of vehicles within the minimum track clearance distance and used to control the operation of the exit gates or for train control purposes.
Exit Gate Operating Mode. For four-quadrant gate systems, the mode of control used to govern the operation of the exit gate.
Fail-Safe. A design practice applied to a system or device such that the result of failure either prohibits the system or device from assuming or maintaining an unsafe state or causes the system or device to assume a state known to be safe regardless of actual prevailing conditions.
False Activation. A condition under which crossing warning devices are activated but there is no train approaching the crossing.
Flagger (Flagging). A person who actively controls the flow of vehicular traffic into and/ or through a temporary traffic control zone using hand-signaling devices or an Automated Flagger Assistance Device (AFAD). In the railroad context, a railroad flagger is a person who is authorized by the railroad to provide warning of the approach of a train or the presence of roadway workers along the right-of-way, and who may be authorized to control rail traffic through a construction zone along a railroad.
Flashing-Light Signals. A warning device consisting of two red signal indications arranged horizontally that are activated to flash alternately when a train is approaching or present at a highway-rail grade crossing.
Functional Classification. Designation of a transportation system into classes or systems by the nature of the service they provide in serving travel needs.
Grade. The rate of ascent or descent of a roadway, expressed as a percent, or the change in roadway elevation per unit of horizontal length.
Grade Crossing (Crossing). The general area where a highway and a railroad and/or light-rail transit route cross at the same level, within which are included the tracks, highway, and traffic control device for traffic traversing that area. In this Handbook, Grade Crossings may be referred to as "Crossings." In this case, it is implied that the crossing is at grade. (See also LRT Grade Crossing.) When the term "Railroad" is used throughout this document; it is inclusive of LRT; however, when "LRT" is the term specifically used, the text is applicable to LRT only.
Grade Separation. A crossing of two roadways, or a roadway and railroad tracks, at different levels that do not physically meet.
Guardrails. A safety barrier intended to deflect an errant vehicle back to the roadway, and prevent an errant vehicle from striking a roadside obstacle that is more hazardous than the guardrail itself.
Highway (Street or Road). A general term for denoting public way for purposes of travel, including the entire area within the ROW.
Highway-Rail Grade Crossing. A location where a highway, road, or street and the railroad ROW cross at the same level, within which are included the railroad tracks, highway, and traffic control devices for highway traffic traveling over the railroad tracks.
Interconnection (Preemption Interconnection). The electrical connection between the railroad crossing warning system and the highway traffic signal controller assembly for preemption.
Light Rail Transit (LRT). LRT is a mode of metropolitan transportation that employs LRT vehicles (commonly known as light rail vehicles, streetcars, or trolleys) that operate on rails in streets in mixed traffic, and LRT traffic that operates in semi-exclusive rights-of-way, or in exclusive rights-of-way. Grade crossings with LRT can occur at intersections or at midblock locations, including public and private driveways.
Locomotive. A piece of on-track equipment other than hi-rail, specialized maintenance, or other similar equipment:
- With one or more propelling motors designed for moving other equipment;
- With one or more propelling motors designed to carry freight or passenger traffic or both; or
- Without propelling motors but with one or more control stands.
Locomotive Cab or Cab Car. The space in a locomotive unit, diesel or electric multiple-unit (DMU/EMU), or push-pull passenger "cab coach" containing the operating controls and providing shelter and seats for the engine crew.
Locomotive Horn. An air horn, steam whistle, or similar audible warning device mounted on a locomotive or control cab car. The terms "locomotive horn," "train whistle," "locomotive whistle," and "train horn" are used interchangeably in the railroad industry.
LRT Grade Crossing (LRT Crossing). The general area where a highway and an LRT route cross at the same level, within which are included the tracks, highway, and traffic control device for traffic traversing that area. (See also Grade Crossing.) When the term "Railroad" is used throughout this document; it is inclusive of LRT; however, when "LRT" is the term specifically used, the text is applicable to LRT only.
Main (Track). A track which is used for through trains operating between stations and terminals as distinguished from a siding which branches from a main line track and is of limited length.
Manual on Uniform Traffic Control Devices (MUTCD). The Manual on Uniform Traffic Control Devices, approved by the Federal Highway Administration, is the national standard for all traffic control devices installed on any street, highway, or bicycle trail open to public travel in accordance with 23 U.S.C 109(d) and 402(a). For the purpose of the MUTCD applicability, "open to public travel" includes toll roads and roads within shopping centers, airports, sports arenas, and other similar business and/or recreation facilities that are privately owned but where the public is allowed to travel without access restrictions. Except for gated toll roads, roads within private gated properties where access is restricted at all times are not included in this definition.
Maximum Highway Traffic Signal Preemption Time. The maximum amount of time needed following initiation of the preemption sequence for the highway traffic signals to complete the ROW transfer and queue clearance, including separation time.
Median. The area between two roadways of a divided highway measured from edge of traveled way to edge of traveled way, excluding turn lanes. The median width may be different between intersections, interchanges, and opposite approaches of the same intersection.
Minimum Track Clearance Distance (MTCD). For standard two-quadrant warning devices, the minimum track clearance distance is the length along a highway at one or more railroad or light rail transit tracks, measured from the highway stop line, warning device, or 12 feet perpendicular to the track center line, to 6 feet beyond the track(s) measured perpendicular to the far rail, along the center line or edge line of the highway, as appropriate, to obtain the longer distance. For Four-Quadrant Gate systems, the minimum track clearance distance is the length along a highway at one or more railroad or light rail transit tracks, measured either from the highway stop line or entrance warning device, to the point where the rear of the vehicle would be clear of the exit gate arm. In cases where the exit gate arm is parallel to the track(s) and is not perpendicular to the highway, the distance is measured either along the center line or edge line of the highway, as appropriate, to obtain the longer distance.
Minimum Warning Time (MWT). The least amount of time the active crossing warning system is designed to remain activated prior to the arrival of a train at a highway-rail grade crossing.
Passive Crossing. A crossing where warnings and traffic control is provided by passive devices such as signs and pavement markings where no Active Grade Crossing Warning System is present.
Pathway. A general term denoting a public way for purposes of travel by authorized users outside the traveled way and physically separated from the roadway by an open space or barrier and either within the highway ROW or within an independent alignment. Pathways include shared-use paths but do not include sidewalks along the roadway traveled way.
Pathway Crossing. Where a pathway and railroad or LRT tracks cross at the same level, within which are included the track, pathway, and traffic control devices for pathway traffic traversing that area.
Pavement Markings. Markings set into the surface of, applied upon, or attached to the pavement for regulating, warning, or guiding traffic.
Preemption Clearance Interval. The part of a traffic signal sequence displayed as a result of a preemption request when vehicles are provided the opportunity to clear the railroad or LRT tracks, or a busway prior to the arrival of the train, or bus for which the traffic signal is being preempted.
Preemption. The transfer of normal operation of traffic signals to a special control mode that interrupts the normal sequence of traffic signal phases to accommodate train operation at or adjacent to the traffic signal-controlled intersection.
Pre-signal. Traffic control signal faces that control traffic approaching a grade crossing in conjunction with the traffic control signal faces that control traffic approaching a highway-highway intersection beyond the tracks. Supplemental near-side traffic control signal faces for the highway-highway intersection are not considered pre-signals. Pre-signals are typically used where the clear storage distance is insufficient to store one or more design vehicles.
Priority. Modification of the normal highway traffic signal operation process to assign who has the right-of-way in the intersection to accommodate train operation at or adjacent to a traffic signal controlled intersection.
Private Crossing. A location where a private highway, road, or street, including associated sidewalks or pathways, crosses one or more railroad tracks.
Public Crossing. A highway-rail or pedestrian grade crossing where a roadway or a pathway, under the jurisdiction of and maintained by a public authority, intersects with the railroad tracks at the same level. No approach may be on private property, unless State law or regulation provides otherwise.
Queue Clearance Time. The time required for a stopped design vehicle that is stopped inside the minimum track clearance distance to start up, move through, and clear the entire minimum track clearance distance. If pre-signals are present, this time must be long enough to allow the vehicle to move through the intersection or to clear the tracks if there is sufficient clear storage distance. If a four-quadrant gate system is present, this time must be long enough to permit the exit gate arm to lower after the design vehicle is clear of the minimum track clearance distance.
Queue Cutter Signal. A traffic control signal that is located just upstream from a crossing where traffic has been observed to queue across the crossing due to a downstream condition. Queue cutters are intended to prevent vehicular queueing across tracks at a crossing and are activated either by detection of a traffic queue getting close to the crossing, or by the approach of a train. A queue cutter signal is not operated as a part of a downstream intersection traffic control signal but is an independently controlled traffic control signal with interconnection to the adjacent crossing warning signal system.
Quiet Zone. A segment of a rail line, within which is situated one or a number of consecutive public highway-rail crossings at which locomotive horns are not routinely sounded per 49 CFR Part 222.(5) (May include private and pedestrian crossings.)
Right-of-Way (ROW). A general term denoting land, property, or interest therein, usually in a strip, acquired for or devoted to transportation purposes. Alternately, "right-of-way" is also a term that confers to a road user or train the priority to proceed in preference to other vehicles or pedestrians, depending upon the rules of the road and traffic control devices in use.
Right-of-Way Transfer Time. The maximum amount of time needed by the traffic signal system to change from its current signal indication to present the track clearance green indication. This includes any railroad or highway traffic signal control equipment time to react to a preemption call and any required traffic control signal green, pedestrian walk and clearance, yellow change, and red clearance intervals for conflicting traffic.
Roadway. The portion of a highway improved, designed, or ordinarily used for vehicular travel and parking lanes, but exclusive of the sidewalk, berm, or shoulder even though such sidewalk, berm, or shoulder is used by persons riding bicycles or other human-power vehicles.
Road User. Vehicle operators, pedestrians including persons with disabilities, or bicyclists within a road or highway.
Separation Time. The portion of highway traffic signal preemption time during which the minimum track clearance distance is clear of vehicular traffic prior to the arrival of the train.
Shoulder. The portion of the roadway adjacent to the traveled way that is primarily intended for accommodation of stopped vehicles for emergency use and for lateral support of base and pavement surface courses.
Sidewalk. That portion of a street between the curb line or the lateral line of a roadway, and the adjacent property line or on easements of private property that is paved or improved and intended for use by pedestrians.
Simultaneous Preemption. Notification of an approaching train is forwarded to the highway traffic signal controller unit or assembly and railroad active crossing warning devices at the same time.
Stopping Sight Distance. The length of highway required to safely stop a vehicle traveling at a given speed.
Swing Gate. A self-closing fence-type gate designed to swing open away from the track area and return to the closed position upon release.
Timed Exit Gate Operating Mode. A mode of operation where the beginning of exit gate descent is based on a predetermined time interval.
Traffic Control Device. A sign, signal, marking, or other device used to regulate, warn, or guide traffic.
Train. One or more locomotives coupled with or without cars that operates on railroad or LRT tracks and to which State law requires that all other traffic must yield the ROW at highway-rail grade crossings.
Traveled Way. The portion of the roadway for the movement of vehicles, exclusive of shoulders.
Volume. The number of vehicles passing a given point during a specified length of time.
Warrants. A threshold condition based upon average or normal conditions that, if found to be satisfied as part of an engineering study, shall result in analysis of other traffic conditions or factors to determine whether a traffic control device or other improvement is justified. Warrants are not a substitute for engineering judgment. The fact that a warrant for a particular traffic control device is met is not conclusive justification for the installation of the device.
Wayside Equipment. The signals, switches, and/or control devices for railroad operations housed within one or more enclosures located along the railroad ROW.
Wayside Horn. A stationary horn located at a highway-rail crossing or pathway crossing, designed to provide, upon the approach of a locomotive or train, audible warning to oncoming motorists of the approach of a train.