USA Banner

Official US Government Icon

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure Site Icon

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Automated Train Operation Interface Requirements Specification Development Summary Report

Document Series
Technical Reports
Federal Railroad Administration
Report Number
Subject Train Control
Automated Train Operation, ATO, Automated Train Operation Support Operation Support System Back Office, ATOSS BO Interface Requirement Specification, IRS, Interoperable Train Control Automated Train Operation Executive, ITC-ATO Ex, Interoperable Train Con

The Federal Railroad Administration contracted Transportation Technology Center, Inc. to define Interface Requirement Specification (IRS) documents for an Interoperable Train Control Automated Train Operation Support System Back Office (ITC-ATOSS BO). This project forms part of a larger Automated Train Operation (ATO) effort in cooperation with the North American railroad industry. The IRS documents define interoperable interfaces between the following:

Interoperable Train Control Automated Train Operation Executive (ITC-ATO Ex) subsystem and ITC-ATOSS BO
ITC-ATOSS BO and Interoperable Train Control Positive Train Control Back Office (ITC-PTC BO)
The goal of the ATO effort is to produce interoperable standards which allow an ATO train developed by any railroad to operate on any railroad’s territory when equipped with the necessary infrastructure and supported by any railroad’s qualified personnel. For an ATO train to be interoperable, it must communicate with each railroad’s ITC-ATOSS BO using a standardized interface. The details of this interface are defined by an IRS.

DOT is committed to ensuring that information is available in appropriate alternative formats to meet the requirements of persons who have a disability. If you require an alternative version of files provided on this page, please contact
Last updated: Thursday, September 28, 2023