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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation
FHWA Highway Safety Programs


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 this document should anticipate possible variations from current information within the FRA databases, which are updated monthly.


The highway-rail crossing is unique as compared to other highway features in that railroads install, operate, and maintain the traffic control devices located at the crossing. Even though much of the cost of designing and constructing crossings, including traffic control devices, is assumed by the public, current procedures place maintenance responsibilities for devices located in the railroad ROW with the railroad. The railroad may be responsible for crossing surface maintenance within the rail and for several feet outside of the rail proper, depending upon State law. The public agency having jurisdiction usually terminates its responsibility for the roadway at the crossing surface.

Traffic control devices on the approach, in most instances, are the responsibility of the public agency. Maintenance-sharing with highway or other local authorities is typically included in C&M agreements developed prior to initiation of final design and construction of improvements. It should be noted that the railroad that usually installs and maintains the active warning system within the railroad right-of-way may require local jurisdictions to assume the added maintenance cost for treatments installed to obtain a Quiet Zone.

The highway agency is usually responsible for traffic control devices that are outside of the railroad ROW. The highway authority is also usually responsible for all types of advance warning signs.


Traffic control devices on approaches to highway-rail crossings require regular inspection and maintenance. Pavement markings, if present, may need to be replaced to maintain adequate retroreflectivity and legibility of word and symbol markings. Signs on the approaches will gradually lose their retroreflectivity and should be inspected as outlined in MUTCD Section 2A.08.

Lighting and active devices should be observed on a regular basis and re-lamped as necessary. Road crews should be on alert for missing or damaged devices. Road crews should also observe the approach roadway to confirm that vegetation does not obscure the traffic control devices from approaching drivers and should trim or cut trees or brush as necessary.

Higher-quality materials, such as improved sign sheeting and preformed tape, thermoplastic, or other durable pavement marking materials, can offer dual benefits by increasing the effectiveness of the devices while reducing the required number of maintenance cycles.


Interconnected traffic signals and AAWS signs should be jointly inspected on a regular basis by State and railroad signal personnel. County or municipal representatives need to be included in this inspection if they share the responsibility for operation or maintenance of the device. Operation of the preempt should be checked any time a railroad or roadway signal maintainer visits the crossing or the highway intersection. Installation of recording devices which monitor train detection and operation of the relays associated with operation of the railroad warning devices should be provided in accordance with current FRA policies. The highway agency and the local law enforcement agency should have a railroad company's telephone number available 24 hours per day to report railroad signal damage or malfunctions.

Relevant Federal requirements include the following regulations, safety advisories, and technical bulletins:

  • 49 CFR 234.261–Requires that a railroad test each highway traffic control signal pre-emption interconnection for which it has maintenance responsibility at least once each month.
  • FRA Technical Bulletin S-12-01–"Guidance Regarding the Appropriate Process for the Inspection of Highway-Rail Grade Crossing Warning System Pre-Emption Interconnections with Highway Traffic Signals": This technical bulletin recommends that the inspector conduct the following: review circuit plans which should show the interconnection and designed preemption time; request maximum right-of-way transfer time (RTT), minimum track clearance green (TCG) interval, and "worst-case" traffic control signal condition from the highway authority, and test pre-emption function by observing a train movement and implementation of the pre-emption function.(55)
  • FRA Safety Advisory 2010-02–"Signal Recording Devices for Highway-Rail Grade Crossing Active Warning Systems that are Interconnected with Highway Traffic Signal Systems"(56): This safety advisory recommends that States, local highway authorities, and railroads install, maintain, and upgrade railroad and highway traffic signal recording devices at crossings. This safety advisory also recommends that States, local highway authorities, and railroads conduct comprehensive periodic joint inspections of highway traffic signal pre-emption interconnections and use information obtained from any railroad and highway traffic signal recording devices during those inspections to determine whether further investigation of any recorded operational anomalies may be warranted. Additional information on recording devices can be found in an Informational Report published by USDOT/FHWA.(57)


As defined by the AASHTO Roadside Design Guide(23), the roadside clear zone is 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. This area allows a driver to stop safely or regain control of a vehicle that has left the roadway.

The AASHTO Roadside Design Guide recommends a clear zone width of 30 to 32 feet for flat, level terrain adjacent to a straight section of a 60-mph highway with an average daily traffic of 6000 vehicles. For steeper slopes, AASHTO recommends a 36 to 44 foot zone. For horizontal curves, AASHTO indicates the clear zone can be increased by up to 50 percent from these figures.

The roadside clear zone serves the dual purpose of increasing the visibility of the crossing and traffic control devices as well as providing a safe recovery area for an errant motorist. The clear zone should be kept free of brush; trees that are more than 4 inches in diameter or that may obscure traffic control devices; and rocks, eroded areas, standing water, or other defects that may entrap an errant vehicle or lead to deterioration of the roadway or track structure.

The maintenance of the sight triangle, beyond highway and railroad ROW, presents a unique problem. Except for portions on the railroad ROW, this often involves private property. The removal of trees, brush, crops, buildings, signs, storage facilities, and other obstructions to the driver's view requires the landowner's permission to access to the property to remove the obstruction.


In addition to typical roadway maintenance, the following are a few special considerations maintenance forces need to keep in mind on roadway approaches to a crossing:

Roadway maintenance equipment can damage crossing surfaces or the adjacent track. Repairs adjacent to the crossing should be done with care.

  • Maintenance personnel should be aware of potential train movements and should be alert for trains. Highway authorities should coordinate with the railroad before conducting roadway maintenance in the vicinity of a crossing, and most railroads require use of a flagman if maintenance activities are conducted within 8 feet of the near rail.
  • Drainage from the crossing or track structure should not be blocked when maintaining pipes and ditches.
  • Snow removal and ice control should be done with care. Snow should not be plowed such that longitudinal piles extend across the tracks. Snowplows can damage crossing surfaces. Chemicals can corrode track and fittings and can short-out track circuits. Snow and slush should not be pushed or carried onto the crossing.
  • Where possible, resurfacing operations should be coordinated with the railroad. Resurfacing lifts should be feathered near the crossing so as not to leave the crossing surface in a hole or dip. Drainage should be checked to assure that the additional roadway height has not directed water onto the crossing surface. All necessary steps should be taken to prevent interference between resurfacing equipment and personnel and trains.


Highway maintenance personnel should be aware of the design, operational, safety, and maintenance issues surrounding highway rail crossings and railroad track structure. In particular, activities which could affect the vertical profile and the interface between the rail right-of-way and the approach roadway should be coordinated with the railroad, and railroads should also coordinate maintenance activities that affect vertical profile with the adjacent highway authority. Pavement markings and signs should be kept up to date and worn, damaged, or missing signs should be replaced. The railroad stop line should be maintained the proper distance from active warning devices and the placement of advance warning signs should be consistent with advance pavement markings. The roadway maintenance supervisor should pay attention to the crossings under his or her jurisdiction and coordinate with the railroad, as necessary, to resolve any problems. If maintenance is being done under a regular program, coordination with affected railroad(s) can address these issues at all relevant crossings. The maintenance supervisor should also contact the crossing program administrator, as necessary, should any needed improvements be identified. Railroad road masters, track supervisors, signal inspectors, and signal maintainers also have a critical role in maintaining features of a highway-rail crossing.


A crossing can become blocked when a train is required to stop for a signal or during switching operations. Even if the crossing is not physically occupied by a train, if a train is standing on the track circuits used to activate the crossing warning system, the flashing-light signals and crossing gates may activate and indicate to road users that a train is approaching the grade crossing. Appendix C to the FHWA/FRA Noteworthy Practices Guide(58) notes the following consequences of blocked crossings:

  • Excessive Roadway Delays
  • Increased Emergency Response Time
  • Truck Traffic Detours onto Local Streets
  • Pedestrians Cutting Through or Under Trains

The FRA regulations do not specifically address the length of time a train may block a grade crossing. However, FRA regulations do address standing (idling) trains that unnecessarily activate grade crossing warning devices such as flashing lights and gate arms.(59) FRA regulations specifically prohibit standing trains, locomotives, or other rail equipment from interfering with the normal functioning of crossing warning devices without first taking measures to provide for the safety of highway traffic.

Responsibility for grade crossings varies among the States. For some, it is divided between several public agencies and the railroad. In other States, jurisdiction is assigned to regulatory agencies such as public utility commissions, public service commissions, or State corporation commissions. Still other States split the authority among State, county, and city governmental agencies that have jurisdiction and responsibility for their respective highway systems.Where there is a conflict between the State law and federal rail safety requirements, the courts have found the State law to be superseded by federal requirements.

Solutions to Blocked Crossings

Appendix C to the Noteworthy Practices Guide addresses potential remedies and encourages States to address these issues in their respective State Action Plans.a Improved communication between the railroad, the local community, and local emergency services personnel is encouraged.

Potential operational changes that a railroad might make include the following:

  • Hold a train outside the congested area until it can move through the grade crossing without stopping
  • Improve management of rail yard traffic to accommodate train movements more efficiently
  • Trains awaiting a crew change should be located in an area that allows minimal frequency of blocked crossings
  • Break a long train by de-coupling two rail cars to allow the resumption of highway traffic when it is anticipated that a grade crossing will be blocked for an extended period

Potential mitigation strategies for chronic grade crossing blockages include the following:

  • Use private and/or public investments to:
    • Add tracks, lengthen sidings, or make other rail infrastructure improvements
    • Create grade separations where the highway is located above or below the tracks
    • Close and consolidate grade crossings to mitigate congestion and improve traffic flow
    • Relocate a rail line to a completely new right-of-way
  • Provide advance warning of blocked grade crossings to motorists and emergency responders and recommend possible alternate routes via Intelligent Transportation Systems
  • Improve communication between, and provide training for, railroads, local communities, State agencies, and emergency responders
  • Encourage local governments to formally consider the potential for new residential or commercial development to generate more highway traffic and how such developments may impact grade crossing use, safety and emergency response

The Railroad Safety Improvement Act (RSIA) of 2008 required the ten states with the highest number of grade crossing collisions during 2006, 2007 and 2008 to develop action plans identifying specific solutions for improving safety at crossings.


The FRA is the custodian for the U.S. DOT National Highway-Rail Crossing Inventory ("Crossing Inventory"), which is a national database of highway-rail and pathway crossings. Regulations governing railroad reporting to the Crossing Inventory were published by FRA in 2015. See Appendix C, Section 1 for further details.

The Guide for Preparing U.S. DOT Crossing Inventory Forms ("Inventory Guide") provides instructions for how to fill out the Crossing Inventory form to submit crossing data to the Crossing Inventory. The Inventory Guide can be found at: