DOT/FRA/ORD-24-08 Final Report | February 2024 

Interoperable Employee-In-Charge Portable Remote 

Terminal (EIC PRT) Summary Report
i 
i 

REPORT DOCUMENTATION 

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number.

PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS.

1. REPORT DATE (DD-MM-YYYY

21/12/2021

2. REPORT TYPE

Technical Report

3. DATES COVERED (From - To)

5/23/2016 – 12/31/2021

4. TITLE AND SUBTITLE

Interoperable Employee-In-Charge Portable Remote Terminal (EIC-PRT)

Summary Report

5a. CONTRACT NUMBER

DTFR5311D00008L

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

6. AUTHOR(S)

Joel Kindt – ORCiD: 0000-0002-8065-763X

Thomas Nast – ORCiD: 0000-0003-1534-3519

5d. PROJECT NUMBER

5e. TASK NUMBER

0028

5f. WORK UNIT NUMBER

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

Transportation Technology Center, Inc.

55500 DOT Road

PO BOX 11130

Pueblo, CO 81001-0130

8. PERFORMING ORGANIZATION 

REPORT NUMBER 

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

U.S. Department of Transportation 

Federal Railroad Administration

Office of Railroad Policy and Development

Office of Research, Development, and Technology (RD&T)

Washington, DC 20590

10. SPONSOR/MONITOR'S ACRONYM(S)

11. SPONSOR/MONITOR'S 

REPORT NUMBER(S) 

DOT/FRA/ORD-24-08

12. DISTRIBUTION/AVAILABILITY STATEMENT 

This document is available to the public through the FRA Web site at http://www.fra.dot.gov

13. SUPPLEMENTARY NOTES

COR: Francesco Bedini

14. ABSTRACT

The Federal Railroad Administration (FRA) sponsored Transportation Technology Center, Inc. (TTCI) to define the requirements for 

Interoperable Employee-In-Charge (EIC) Portable Remote Terminal (PRT) functionality for use with Positive Train Control (PTC) 

systems. The Interoperable EIC-PRT is a safety overlay system that integrates with PTC to protect maintenance-of-way (MOW) 

workers by placing the entry of trains into work zones (WZ) under the control of the EIC. This research was conducted between 2016 

and 2021. Collaborating with the North American railroad industry, the team developed systems engineering documents defining the 

EIC PRT system, including the interoperable requirements for the EIC PRT, EIC Server and Onboard segments. Additionally, the 

team developed a prototype Roadway Worker Terminal (RWT) application following the interoperable requirements and tested the 

application to demonstrate requirement compliance.

15. SUBJECT TERMS

Positive Train Control (PTC), Employee-in-Charge Portable Remote Terminal (EIC-PRT), work zone, electronic instructions

16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF 

ABSTRACT 

18. NUMBER 

OF 

PAGES

18

19a. NAME OF RESPONSIBLE PERSON

Thomas Nast, Principal Investigator II a. REPORT

Unclassified

b. ABSTRACT

Unclassified

c. THIS PAGE

Unclassified 19b. TELEPHONE NUMBER (Include area code)

719-584-0658

Standard Form 298 (Rev. 8/98)

Prescribed by ANSI Std. Z39.18
ii

METRIC/ENGLISH CONVERSION FACTORS

ENGLISH TO METRIC METRIC TO ENGLISH

LENGTH (APPROXIMATE) LENGTH (APPROXIMATE)

1 inch (in) = 2.5 centimeters (cm) 1 millimeter (mm) = 0.04 inch (in) 

1 foot (ft) = 30 centimeters (cm) 1 centimeter (cm) = 0.4 inch (in) 

1 yard (yd) = 0.9 meter (m) 1 meter (m) = 3.3 feet (ft)

1 mile (mi) = 1.6 kilometers (km) 1 meter (m) = 1.1 yards (yd)

1 kilometer (km) = 0.6 mile (mi)

AREA (APPROXIMATE) AREA (APPROXIMATE)

1 square inch (sq in, in2) = 6.5 square centimeters (cm2) 1 square centimeter (cm2) = 0.16 square inch (sq in, in2) 

1 square foot (sq ft, ft2) = 0.09 square meter (m2) 1 square meter (m2) = 1.2 square yards (sq yd, yd2)

1 square yard (sq yd, yd2) = 0.8 square meter (m2) 1 square kilometer (km2) = 0.4 square mile (sq mi, mi2)

1 square mile (sq mi, mi2) = 2.6 square kilometers (km2) 10,000 square meters (m2) = 1 hectare (ha) = 2.5 acres 

1 acre = 0.4 hectare (he) = 4,000 square meters (m2) 

MASS - WEIGHT (APPROXIMATE) MASS - WEIGHT (APPROXIMATE)

1 ounce (oz) = 28 grams (gm) 1 gram (gm) = 0.036 ounce (oz)

1 pound (lb) = 0.45 kilogram (kg) 1 kilogram (kg) = 2.2 pounds (lb)

1 short ton = 2,000 pounds (lb) = 0.9 tonne (t) 1 tonne (t) =

=

1,000 kilograms (kg) 

1.1 short tons

VOLUME (APPROXIMATE) VOLUME (APPROXIMATE)

1 teaspoon (tsp) = 5 milliliters (ml) 1 milliliter (ml) = 0.03 fluid ounce (fl oz)

1 tablespoon (tbsp) = 15 milliliters (ml) 1 liter (l) = 2.1 pints (pt) 

1 fluid ounce (fl oz) = 30 milliliters (ml) 1 liter (l) = 1.06 quarts (qt) 

1 cup (c) = 0.24 liter (l) 1 liter (l) = 0.26 gallon (gal) 

1 pint (pt) = 0.47 liter (l)

1 quart (qt) = 0.96 liter (l)

1 gallon (gal) = 3.8 liters (l) 

1 cubic foot (cu ft, ft3) = 0.03 cubic meter (m3) 1 cubic meter (m3) = 36 cubic feet (cu ft, ft3) 

1 cubic yard (cu yd, yd3) = 0.76 cubic meter (m3) 1 cubic meter (m3) = 1.3 cubic yards (cu yd, yd3)

TEMPERATURE (EXACT) TEMPERATURE (EXACT)

[(x-32)(5/9)] °F = y °C [(9/5) y + 32] °C = x °F

QUICK INCH - CENTIMETER LENGTH CONVERSION

0 1 2 3 4 5

Inches

Centimeters 0 1 2 3 4 5 6 987 1110 1312

QUICK FAHRENHEIT - CELSIUS TEMPERATURE CONVERSIO

 -40° -22° -4° 14° 32° 50° 68° 86° 104° 122° 140° 158° 176° 194° 212°

 

°F

 °C -40° -30° -20° -10° 0° 10° 20° 30° 40° 50° 60° 70° 80° 90° 100°

For more exact and or other conversion factors, see NIST Miscellaneous Publication 286, Units of Weights and 

Measures. Price $2.50 SD Catalog No. C13 10286 Updated 6/17/98
iii

Acknowledgements

Transportation Technology Center, Inc. recognizes the substantial technical and resource 

contributions to this project by BNSF Railway and the collaborative efforts and assistance 

provided by the railroad advisory group. 
iv

Contents

Executive Summary ........................................................................................................................ 1

1. Introduction ................................................................................................................. 2

1.1 Objectives .................................................................................................................... 4

1.2 Overall Approach ........................................................................................................ 5

1.3 Scope ........................................................................................................................... 5

1.4 Organization of the Report .......................................................................................... 6

2. Project Accomplishments ............................................................................................ 7

3. Conclusion and Recommended Next Steps ................................................................. 8

4. References ................................................................................................................... 9

Appendices ................................................................................................................................... 10

Abbreviations and Acronyms ....................................................................................................... 11
v 

Illustrations

Figure 1. EIC PRT Architecture (from EIC-PRT CONOPS 1.5) ................................................... 3

Figure 2. EIC Instructions to Trains (from EIC PRT CONOPS 1.5) ............................................. 4
1 

Executive Summary

The Federal Railroad Administration (FRA) sponsored Transportation Technology Center, Inc. 

(TTCI) to define the requirements for Interoperable Employee-In-Charge (EIC) Portable Remote 

Terminal (PRT) functionality for use with Positive Train Control (PTC) systems. The 

Interoperable EIC-PRT is a safety overlay system that integrates with PTC to protect maintenanceof-way (MOW) workers by placing the entry of trains into work zones (WZ) under the control of 

the EIC. This research was conducted between 2016 and 2021.

Collaborating with the North American railroad industry, the team developed systems 

engineering documents defining the EIC PRT system, including the interoperable requirements 

for the EIC PRT, EIC Server and Onboard segments. Additionally, the team developed a 

prototype Roadway Worker Terminal (RWT) application following the interoperable 

requirements and tested the application to demonstrate requirement compliance. 
2 

1. Introduction

In the Rail Safety Improvement Act of 2008 (RSIA 2008), Congress mandated that each Class I 

freight railroad or other entity providing regularly scheduled intercity or commuter rail passenger 

transportation must implement a Positive Train Control (PTC) system on designated main lines 

with regularly scheduled passenger service or over which designated hazardous materials are 

transported. PTC systems, as defined by RSIA 2008, are designed to prevent: 

• Train-to-train collisions

• Over-speed derailments

• Incursions into established work zone (WZ) limits

• Movement of a train through a switch left in the wrong position

Since 2008, the U.S. railroad industry has devoted a significant amount of financial and human 

resources to develop safe and functional PTC systems, and railroads have encountered an array 

of technical and nontechnical challenges in its design and deployment. Early PTC development 

demonstrated the need for WZ boundaries to be enforced by the PTC system until the Employee 

In Charge (EIC) of a maintenance-of-way (MOW) work gang provides permission for an 

approaching train to enter the WZ.

The EIC Portable Remote Terminal (EIC PRT) system provides the EIC with a PTC system

interface that allows them to control train entry and movement through the EIC’s WZ. Using the 

EIC PRT system, the EIC can issue PTC-enforceable instructions to a train, including permission 

for a train to enter a WZ and speed limits for a train while operating within a WZ.

The EIC PRT system can increase protection of MOW personnel by providing the PTC onboard 

segment with enforceable EIC instructions equivalent to those issued by voice to the train crew.

The first build addresses the following EIC PRT project safety objectives:

• Prevent failure of train from stopping at WZ boundary, as could occur when the 

locomotive engineer incorrectly indicates permission received to travel through the WZ 

• Prevent train over-speed within WZ limits

• Mitigate train/gang collisions within WZ limits

• Mitigate EIC working outside of WZ protected time, by providing warnings when a WZ 

is about to expire (configurable option) 

• Prevent instructions to the Onboard by unauthorized third party 

The Interoperable EIC-PRT system architecture is illustrated in Figure 1. The EIC PRT 

application is independent of the communication network used to transport messages between 

the EIC PRT and the EIC Server.
3 

Figure 1. EIC PRT Architecture (from EIC-PRT CONOPS 1.5)

Figure 2 illustrates how an EIC uses the EIC PRT system to provide instructions to a PTCequipped train as it approaches a WZ. Note that, as illustrated, the EIC PRT is an overlay to 

existing operating practices, therefore voice communication between an EIC and a train crew is 

maintained. 

FRA has previously funded projects supporting the development and integration of EIC PRT 

functionality with BNSF Railway’s PTC system. Under these prior efforts, researchers 

developed and tested EIC PRT functionality, but variations in operating rules and railroadspecific features of Interoperable Train Control (ITC)-compliant PTC systems required 

modification of the EIC PRT functional definition and implementation to support industry-wide 

interoperability. 

In this research, conducted between 2016 and 2021, the team modified the EIC PRT system 

engineering documentation and prototype application to satisfy the interoperability requirements 

of the North American freight railroad industry and other ITC users. 
4 

Figure 2. EIC Instructions to Trains (from EIC PRT CONOPS 1.5)

1.1 Objectives

The key objectives of this project were: 

• Preparation of Interoperable EIC PRT engineering documents 

• Submission of documents to the Association of American Railroads (AAR) for 

consideration for the Manual of Standards and Recommended Practices (MSRP) 

publication 

• Implementation of EIC PRT test tools

• Implementation of the Roadway Worker Terminal (RWT) application

• Unit testing of the RWT application

• Laboratory Integration Nearest Neighbor (LINN) testing of the interoperable EIC PRT

Lift 0 Mph Target Over WZ

Display and Enforce Permissive EIC Instructions

Train Enters Approach Zone 

Display WZ with 0 MPH Target from Time WZ Enters the Track Map

Train Enters Query Zone 

Query For WZ Control Status

Crew Indicates They Need Instructions for the WZ

Track Bulletin

Pending 

Request

Notification

Voice Communication :

Crew Requests Permission

And EIC Gives Instructions 

Instruction Request Instruction Request

EIC Instructions EIC Instructions

Enter and

Approve 

Instructions

Confirm

Match

Crew Confirmation of 

Received EIC Instructions

Request

Confirmation

Confirm 

Permissive 

Instructions

EIC Confirmation of

Permissive Instructions

Displays Electronic Instructions

Request Confirmation Instructions Match 

EIC Issues Permissive Instructions

WZ Control Status = Electronic

Onboard Acknowledgment Onboard Acknowledgment

Locomotive Segment Office Segment Roadway Worker Segment

Instructions Request ACK Instructions Request ACK

Crew Confirmation of 

Received EIC Instructions

EIC Confirmation of

Permissive Instructions
5 

• Revision of EIC PRT safety documentation (e.g., critical assumptions, hazard log, risk 

assessment, etc.)

1.2 Overall Approach

Researchers worked with a technical advisory group (TAG) comprised of representatives from

Class I freight railroads and FRA to revise the EIC PRT requirements to satisfy the 

interoperability requirements of the railroad industry and ITC principles. The TAG members 

participated in weekly EIC PRT development teleconferences and design review meetings. Team

efforts focused on the overall system definition and development of the EIC PRT RWT

application. The TAG approved all Interoperable EIC PRT documents before they were 

submitted to AAR for possible inclusion in the MSRP.

1.3 Scope 

The Interoperable EIC PRT project effort included: 

• Development of Interoperable EIC PRT system definition documentation

• Development of Interoperable EIC PRT RWT application software

• Testing on the EIC PRT RWT application software 

• Continuation of the EIC PRT safety assessment effort, limited by dependencies on the 

design within the back office and onboard 

Interoperable EIC PRT definition documentation produced in this project included: 

• Interoperable EIC PRT Concept of Operations (CONOPS)

• Interoperable EIC PRT RWT – Back Office System interface control document

• Interoperable EIC PRT Locomotive Onboard – Back Office System interface control 

document 

• Interoperable EIC PRT RWT Requirements 

• Interoperable EIC PRT Back Office Segment Requirements

• Interoperable EIC PRT Locomotive Onboard Segment Requirements

The publication of EIC PRT design documentation and materials produced in this project in the 

AAR MSRP is out of the scope of this effort and is at the discretion of the AAR. 

Additional documentation produced in this project includes: 

• EIC PRT RWT software requirements

• EIC Server Simulator requirements

• EIC PRT RWT unit test cases and test artifacts

• Preliminary Hazard Analysis (PHA)

• Configurable parameter safety assessment

All documentation is available upon request from FRA.
6 

1.4 Organization of the Report

This is a summary report that highlights the results of the Interoperable EIC PRT project. This 

report is organized as follows:

• Section 2 provides an overview of the interoperable EIC PRT deliverables. 

• Section 3 provides project conclusions and recommendations for next steps.

• Appendices A through F contain a set of draft interoperable EIC PRT systems 

engineering documents. Appendices G through H contain the results and artifacts of the 

interoperable EIC PRT unit testing. Appendix I contains current drafts of the EIC PRT 

safety documentation. All appendices are available upon request.
7 

2. Project Accomplishments

The team collaborated with the railroad industry for this research. Researchers conducted 

working sessions to address technical details as they arose. The team held formal design review 

meetings, including a Preliminary Design Review (PDR) and a Critical Design Review (CDR), 

hosted by BNSF Railway. The participants in these design review meetings included 

representatives from the research team, FRA, Class I freight railroads, an onboard supplier, the 

developer for the EIC PRT application, and a safety consultant. 

Through this collaborative work, the research team produced EIC PRT systems engineering 

documents which were submitted to the TAG for final review and approval. After iterative 

review, the TAG approved the systems engineering documents and the research team then 

submitted the documents to AAR for possible inclusion in the MSRP.

The team also modified the EIC PRT roadway worker application to satisfy industry-approved 

interoperability requirements and testing. Researchers developed unit test cases using a 

requirements verification and criteria matrix (RVCCM) and performed unit testing of the EIC 

PRT RWT application.

The following Interoperable EIC PRT systems engineering and requirements documents were 

produced: 

• Interoperable EIC PRT CONOPS

• Interoperable EIC PRT Roadway Worker Segment Requirements 

• Interoperable EIC PRT Back Office Segment Requirements

• Interoperable EIC PRT Locomotive Onboard Segment Requirements

• Interoperable EIC PRT RWT – Back Office System Interface Control Document

• Interoperable EIC PRT Locomotive Onboard Segment – Back Office System Interface 

Control Document1

• EIC PRT RWT Application Software Requirements Document 

All documentation is available by request from FRA.

LINN tests are usually conducted between adjacent system segments, such as the EIC PRT RWT 

application and the EIC server. However, development of EIC PRT functions within PTC back 

office and PTC locomotive onboard equipment was delayed, impacting the LINN testing 

schedule. As a result, LINN tests were not completed as part of this project.

The finalization of the EIC PRT Fault Tree Analysis (FTA) and integration of the EIC PRT fault 

tree with the PTC onboard fault tree has not yet been completed due to similar delays. 

1 This document was produced by Wabtec with the input/guidance of the TAG and the research team, and was 

included in the documentation provided to AAR. 
8 

3. Conclusion and Recommended Next Steps

The research team worked with representatives from the rail industry to define and develop the 

Interoperable EIC PRT system to enhance the safety benefit of PTC. 

The team recommends several steps to facilitate the integration of the EIC PRT system into 

current railroad operations with PTC. These tasks can help the industry deploy the EIC PRT 

system in interoperable operations. 

1. LINN testing between the RWT and back office (once the back-office segment EIC PRT 

function support is implemented)

2. LINN testing between the onboard and back-office segments (once the back office and 

onboard EIC PRT function support is implemented)

3. Field integration testing

4. Field service testing with user experience feedback

5. Complete safety assessment

The research team also recommends further revision of the EIC PRT documents developed in 

this research when integrating the EIC PRT system into high automation train operation, 

including high automation addenda for the EIC PRT systems engineering documents. These

addenda should describe how the previously developed concepts and the EIC PRT requirements 

should be modified to minimize required crew prompts during high automation of the EIC PRT. 
9 

4. References

1. Rail Safety Improvement Act of 2008. Pub. L. No. 110-432, 122 stat. 4848. 
10 

Appendices

The following appendices are available by request from FRA.

Appendix A: Interoperable EIC PRT Concept of Operations 

Appendix B: Interoperable EIC PRT Roadway Worker Application Requirements

Appendix C: Interoperable EIC PRT Back Office Segment Requirements

Appendix D: Interoperable EIC PRT Locomotive Onboard Segment Requirements 

Appendix E: Interoperable EIC PRT Roadway Worker Terminal – Back Office System Interface 

Control Document 

Appendix F: EIC PRT RWT Application Software Requirements Document 

Appendix G: EIC PRT Roadway Worker Terminal Application Unit Test Plans and Test Cases

Appendix H: Summary of EIC PRT Roadway Worker Terminal Application Unit Test Results

Appendix I: EIC PRT Safety Assessment Documents
11 

Abbreviations and Acronyms

ACRONYM DEFINITION

AAR Association of American Railroads

BNSF Burlington Northern Santa Fe Railway Company

BOS Back Office Server

CDR Critical Design Review

CFR Code of Federal Regulations

CONOPS Concept of Operations

EIC Employee-in-Charge

FRA Federal Railroad Administration

FTA Fault Tree Analysis

ITC Interoperable Train Control

LINN Laboratory Integration Nearest Neighbor

MOW Maintenance of Way

MSRP Manual of Standards and Recommended Practices

PDR Preliminary Design Review

PHA Preliminary Hazard Analysis

PRT Portable Remote Terminal

PTC Positive Train Control

RSIA ‘08 Rail Safety Improvement Act of 2008

RVCCM Requirements Verification Conditions and Criteria Matrix

RWT Roadway Worker Terminal

SRS Software Requirements Specification

SSPP System Safety Program Plan

TAG Technical Advisory Group

TBD To Be Determined

WZ Work Zone