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IEEE 1570-2002 - Standard for the Interface Between the Rail Subsystem and the Highway Subsystem at a Highway Rail Intersection


This Fact Sheet was written on December 13, 2005. The status of the standard at the time was: Published in October 2002.

This Fact Sheet was last verified on October 07, 2009

 Check the ITS Standards Search to see if there has been subsequent development activity.

Overview

The IEEE Standard for the Interface Between the Rail Subsystem and the Highway Subsystem at a Highway Rail Intersection is applicable to the interface between the railroad side and the highway side of a highway-rail grade crossing. A highway rail intersection (HRI) is defined as the "general area where a highway and a railroad’s right of way cross at the same level, within which are included the railroad tracks, a highway, and traffic control devices for highway traffic traversing that area." One of the prime purposes of this interface has been to preempt traffic signal operation when a train is approaching in order to allow traffic to clear from the vicinity of the crossing.

Railroad and roadway data communications systems have evolved essentially independently of one another, driven by requirements unique to their respective applications. This standard specifies the rules for communicating (called protocols) and the vocabulary (called messages and data) necessary to allow wayside (rail) equipment and roadway equipment to operate with each other as a system, without unduly impacting existing communication protocols currently used in railway and roadway data communications.

What are these standards for?

IEEE 1570-2002, Standard for the Interface Between the Rail Subsystem and the Highway Subsystem at a Highway Rail Intersection, specifies the communications protocols and commands, responses and information necessary for the exchange of information across the interface between the rail and highway systems at a highway rail intersection. Previous standards addressed analog interfaces between these systems; this IEEE 1570-2002 standard extends that information to include digital data communications.

This standard defines the messages and data used to exchange information between the wayside and traffic controller equipment about the operational state of the rail crossing (train presence, entrance and exit gate status, warning system activated), approaching trains (train classification, time of arrival and departure, train length, direction of travel), wayside and traffic controller equipment status, and obstacles in the roadway where it crosses the railroad tracks.

Who uses them?

This standard should be used by transportation, rail, and traffic engineers involved with the design, specification, selection, procurement, installation, testing, operation, and maintenance of wayside and traffic control equipment at a highway rail intersection. ITS product hardware and software designers and application (computer program) developers should find this standard especially relevant to their efforts.

How are they used?

IEEE 1570-2002, Standard for the Interface Between the Rail Subsystem and the Highway Subsystem at a Highway Rail Intersection defines a vocabulary of "messages and data" used to assure that wayside equipment and traffic control equipment "speak" a common language. A message must be understood by the device it was intended for, and especially important, it must not be misunderstood or misinterpreted during safety-critical situations. Message definitions unambiguously define the content, terminology, value, and format of commands, responses, and information affecting communications between wayside and traffic control systems at the highway rail intersection.

This standard specifies the industry standard communications profiles (see related documents below) which provide the communications channel for information transfer between devices. More than one set of protocols is specified to provide equipment manufacturers the flexibility to implement the HRI interface in a manner that best fits the circumstances of a particular installation.

Scope

Communication between the rail wayside equipment and traffic control equipment is accomplished by using the messages and communications profiles defined in this standard, IEEE 1570-2002, Standard for the Interface Between the Rail Subsystem and the Highway Subsystem at a Highway Rail Intersection. These objects define the information, commands and responses that must be understood by the devices at both ends of the communications channel. This standard defines messages to support four different types of information exchange: operational state of the rail crossing (train presence, entrance and exit gate status, warning system activated), approaching train information (train classification, time of arrival and departure, train length, direction of travel), wayside and traffic controller equipment status, and obstacles in the roadway where it crosses the railroad tracks. User-specific wayside and traffic controller equipment messages are also supported.

The following set of standards and documents, while not part of the ITS standards, should also be considered when using this standard:

How to obtain Standards
Institute of Electrical and Electronics Engineers
732-562-3800
http://www.ieee.org