Standards for Development and Use of Processor-Based Signal and Train Control Systems, 11052-11108 [05-3955]

Agencies

• Federal Railroad Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 70, Number 43 (Monday, March 7, 2005)]
[Rules and Regulations]
[Pages 11052-11108]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-3955]



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Part II





Department of Transportation





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Federal Railroad Administration



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49 CFR Parts 209, 234, and 236



Standards for Development and Use of Processor-Based Signal and Train 
Control Systems; Final Rule

Federal Register / Vol. 70, No. 43 / Monday, March 7, 2005 / Rules 
and Regulations

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DEPARTMENT OF TRANSPORTATION

Federal Railroad Administration

49 CFR Parts 209, 234, and 236

[Docket No. FRA-2001-10160]
RIN 2130-AA94


Standards for Development and Use of Processor-Based Signal and 
Train Control Systems

AGENCY: Federal Railroad Administration (FRA), Department of 
Transportation (DOT).

ACTION: Final rule.

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SUMMARY: FRA is issuing a performance standard for the development and 
use of processor-based signal and train control systems. The rule also 
covers systems which interact with highway-rail grade-crossing warning 
systems. The rule establishes requirements for notifying FRA prior to 
installation and for training and recordkeeping. FRA is issuing these 
standards to promote the safe operation of trains on railroads using 
processor-based signal and train control equipment.

DATES: This rule is effective June 6, 2005. The incorporation by 
reference of a certain publication listed in the rule is approved by 
the Director of the Federal Register as of June 6, 2005.

ADDRESSES: Except for good cause shown, any petition for 
reconsideration of any part of this rule must be submitted not later 
than May 6, 2005. Any petition for reconsideration should reference FRA 
Docket No. FRA-2001-10160 and be submitted in triplicate to the Docket 
Clerk, Office of Chief Counsel, FRA, 1120 Vermont Avenue, NW., Mail 
Stop 10, Washington, DC 20590. Petitions, received by the FRA Docket 
Clerk will be sent to the DOT Docket Management System (DMS) located on 
the Plaza level of the Nassif Building at the Department of 
Transportation. You can review public dockets, including any petitions 
for reconsideration received there between the hours of 9 a.m. and 5 
p.m., Monday through Friday, except Federal holidays. You can also 
review any petition for reconsideration on-line at the DMS Web site at 
https://dms.dot.gov. Please note that anyone is able to search the 
electronic form of all submissions into any of FRA's dockets by the 
name of the individual making the submission (or signing the 
submission, if submitted on behalf of an association, business, labor 
union, etc.). You may review DOT's complete Privacy Act Statement in 
the Federal Register published on April 11, 2000 (volume 65, number 70; 
pages 19477-78), or you may visit https://dms.dot.gov.

FOR FURTHER INFORMATION CONTACT: Tom McFarlin, Staff Director, Signal 
and Train Control Division, Office of Safety, FRA, 1120 Vermont Avenue, 
NW., Mail Stop 25, Washington, DC 20590 (telephone: 202-493-6203); or 
Melissa Porter, Office of Chief Counsel, FRA, 1120 Vermont Avenue, NW., 
Mail Stop 10, Washington, DC 20590 (telephone: 202-493-6034).

SUPPLEMENTARY INFORMATION:

Table of Contents for Supplementary Information

I. Introduction
II. Statutory Background
III. Regulatory Background
IV. RSAC
    A. Overview
    B. The PTC Working Group
V. Discussion of Alternatives Considered and the Rationale for the 
Option Selected
    A. Performance Standards vs. Prescriptive Standards
    B. Evaluation of Performance-Based Approach
    C. Advantages of a Performance Standard; Consideration of 
Disadvantages
    D. Analysis of Risk Associated With Train Control Technologies
    E. Choice of Type of Performance Standard
    F. Options for Demonstrating Compliance With the Performance 
Standard
VI. Proceedings to Date
VII. Comments and Conclusions on General Issues
    A. Background and RSAC Process
    B. The Performance-Based Approach
    C. The Performance Standard--What Will Be the ``Base Case'' for 
Comparison?''
    D. How Does This Rule Affect Locomotive Electronics and Train 
Control?
VIII. Section-by-Section Analysis
IX. Regulatory Impact
    A. Executive Order 12866 and DOT Regulatory Policies and 
Procedures
    B. Anticipated Costs and Benefits
    C. Regulatory Flexibility Act
    D. Paperwork Reduction Act
    E. Environmental Impact
    F. Federalism Implications
    G. Compliance with the Unfunded Mandates Reform Act of 1995
List of Subjects

I. Introduction

    FRA is issuing a performance standard for processor-based signal 
and train control systems. FRA began the process of developing a rule 
in 1997 when its Railroad Safety Advisory Committee (RSAC) was tasked 
with developing a proposed rule for FRA's consideration. RSAC made 
consensus recommendations to FRA on a proposed rule; FRA agreed to 
these recommendations and published them as a notice of proposed 
rulemaking (NPRM) on August 10, 2001 (66 FR 42352). FRA received quite 
a few public comments on the NPRM. This notice responds to comments on 
the NPRM and issues the final rule. The standards grew out of the 
proposed rule requiring that processor-based signal and train control 
systems meet or exceed the safety level of the traditional signal 
systems they replace. The preamble discusses the statutory background, 
the regulatory background, the RSAC proceedings, the alternatives 
considered and the rationale for the option selected, the proceedings 
to date, as well as the comments and conclusions on general issues. 
Other comments and resolutions are discussed within the corresponding 
section-by-section analysis.

II. Statutory Background

    FRA has broad statutory authority to regulate all areas of railroad 
safety. 49 U.S.C. 20103(a); 49 CFR 1.49. The Federal Railroad Safety 
Act of 1970, Public Law 91-458, contained this broad grant of authority 
and supplemented the older rail safety laws then in existence. The 
older safety laws had been enacted in a piecemeal approach and 
addressed specific fields of railroad safety. For instance, the Signal 
Inspection Act, 49 U.S.C. 26 (recodified at 49 U.S.C. 20502 et seq. 
(1994)), has governed the installation and removal of signal equipment 
since its enactment August 26, 1937. Until July 5, 1994, the Federal 
railroad safety statutes existed as separate acts found primarily in 
Title 45 of the United States Code. On that date all of the acts were 
repealed and their provisions were recodified into Title 49 Chapters 
201-213.
    Pursuant to its general statutory rulemaking authority, FRA 
promulgates and enforces rules as part of a comprehensive regulatory 
program to address the safety of railroad track, signal systems, 
railroad communications, rolling stock, operating practices, passenger 
train emergency preparedness, alcohol and drug testing, locomotive 
engineer certification, and workplace safety. In the area of railroad 
signal and train control systems, FRA has issued regulations, found at 
49 CFR part 236 (``part 236''), addressing topics such as the security 
of signal apparatus housings against unauthorized entry (49 CFR 236.3), 
location of roadway signals (49 CFR 236.21), and the testing of relays 
(49 CFR 236.106). Hereafter all references to parts and sections shall 
be parts and sections located in Title 49 of the Code of Federal 
Regulations.
    FRA continually reviews its regulations and revises them as needed 
to keep up with emerging technology. FRA's need to review its 
regulatory

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scheme with respect to emerging technology in the signal and train 
control arena was acknowledged by Congress in Section 11 of the Rail 
Safety Enforcement and Review Act (RSERA) (Pub. L. 102-365, Sep. 3, 
1992), entitled ``Railroad Radio Communications.'' Section 11(a) of 
RSERA mandated that the Secretary conduct a safety inquiry to assess, 
among other areas,
    (6) The status of advanced train control systems that are being 
developed, and the implications of such systems for effective railroad 
communications; and
    (7) The need for minimum Federal standards to ensure that such 
systems provide for positive train separation and are compatible 
nationwide.

106 Stat. 980. Section 11(b) required the Secretary to

submit to Congress within 4 months after the completion of such 
inquiry a report on the results of the inquiry along with an 
identification of appropriate regulatory action and specific plans 
for taking such action.

Id.
    FRA conducted the inquiry required by RSERA and submitted a 
comprehensive Report to Congress on July 8, 1994, entitled Railroad 
Communications and Train Control (1994 PTC Report). A copy of this 1994 
PTC Report is in the docket of this rulemaking. As part of the 1994 PTC 
Report, FRA called for implementation of an action plan to deploy PTC 
systems. The report forecast substantial benefits of advanced train 
control technology to support a variety of business and safety 
purposes, but noted that an immediate regulatory mandate for PTC could 
not be currently justified based upon normal cost/benefit principles 
relying on direct safety benefits. The report outlined an aggressive 
Action Plan implementing a public/private sector partnership to explore 
technology potential, deploy systems for demonstration, and structure a 
regulatory framework to support emerging PTC initiatives.
    Since 1994, the Congress has appropriated and FRA has committed 
approximately $40 million through the Next Generation High Speed Rail 
Program and the Research and Development Program to support 
development, testing and deployment of PTC prototype systems in 
Illinois, Alaska, and the Eastern railroads' on-board electronic 
platforms. As called for in the Action Plan, the FRA also launched an 
effort to structure an appropriate regulatory framework for 
facilitating implementation of PTC technology and for evaluating future 
safety needs and opportunities. For such a task, FRA desired input from 
the developers, prospective purchasers and operators of this new 
technology. Thus, in September of 1997, the Federal Railroad 
Administrator asked RSAC to address several issues involving PTC, 
including the development of performance standards for PTC systems. 
RSAC's involvement in this rulemaking will be discussed later in the 
preamble.
    Since the issuance of FRA's 1994 PTC Report, Congress has twice 
requested the Secretary of Transportation to submit additional reports 
on PTC; first in 1994, and more recently in 2003. In 1994, Congress 
directed the Secretary to submit a progress report.

    The Secretary of Transportation shall submit a report to the 
Congress on the development, deployment, and demonstration of 
positive train control systems by December 31, 1995.

49 U.S.C. 20150. On May 17, 2000, FRA submitted a letter report 
responding to Section 20150 (2000 PTC Report). A copy of the 2000 PTC 
Report is in the docket of this rulemaking. The report noted the 
progress being made toward the deployment of PTC systems but concluded 
that deployment on the entire national rail system cannot be justified 
on safety grounds alone. FRA indicated that it would continue to 
encourage railroads to deploy PTC voluntarily. The report noted that 
RSAC, at FRA's request, had begun to address the PTC issue, and had 
issued a report to FRA in September 1999 (1999 RSAC Report) entitled 
Implementation of Positive Train Control Systems that detailed current 
PTC system projects, estimated accidents preventable by PTC systems, 
and estimated the costs and benefits of PTC systems as applied to the 
major railroads.
    The 1999 RSAC Report confirmed the core PTC safety functions 
described in the 1994 PTC Report (prevent train-to-train collisions; 
enforce speed restrictions and temporary slow orders; and provide 
protection for roadway workers and their equipment operating under 
specific authorities). It also referred to additional safety functions 
that might be included in some PTC architecture (e.g., warning of on-
track equipment operating outside the limits of authority; enforcement 
of hazard detection warnings; and a future capability for generating 
data for transfer to highway users to enhance warning at highway-rail 
grade crossings).
    The 1999 RSAC Report found that railroad safety benefits of PTC 
could not support the investments necessary to deploy the system. The 
report estimated that PTC deployment on the Class 1 railroads would 
cost about $1.2 billion to equip the lines with a level 1 type PTC 
system (address core PTC functions only), and about $7.8 billion to 
equip the lines with a level 4 type PTC system (increased functionality 
addressing additional safety monitoring systems and enhanced traffic 
management capabilities). These costs are total discounted life cycle 
costs, including procurement, installation, and maintenance, over 20 
years. The 20 year total discounted benefits from avoided accidents 
ranged from about $500 million for a level 1 PTC system, to about $850 
million for a level 4 PTC system. The Committee was not able to reach 
conclusions regarding the non-safety benefits of PTC-related 
technologies.
    As part of the FRA appropriations for fiscal year 2003, Congress 
requested FRA to update cost/benefit numbers contained in the 2000 PTC 
Report to Congress. The Conference Report on the Consolidated 
Appropriations Resolution, 2003 (Pub. L. 108-7) provided in pertinent 
part as follows:

    Positive train control.--The conferees direct FRA to submit an 
updated economic analysis of the costs and benefits of positive 
train control and related systems that takes into account advances 
in technology and system savings to carriers and shippers as well as 
other cost savings related to prioritized deployment of these 
systems, as proposed by the Senate. This analysis must be submitted 
as a letter report to the House and Senate Committees on 
Appropriations by October 1, 2003.

    H.R. Rep. No. 108-10, 108th Cong. 1st Sess. 1286-7. FRA submitted 
the requested PTC letter report to Congress on August 18, 2004 and a 
copy of the report is in the docket of this rulemaking. The report 
indicates that substantial public benefits would likely flow from the 
installation of PTC systems on the railroad system, although the total 
amount of these benefits is subject to debate. The report reaffirmed 
the conclusions reached in the 1994 and 2000 PTC Reports that the 
safety benefits of PTC systems are relatively small in comparison to 
the huge costs of installing the PTC systems.
    In light of the cost/benefit numbers, an immediate regulatory 
mandate for PTC could not be currently justified based upon normal 
cost/benefit principles relying on direct railroad safety benefits. FRA 
has, therefore, chosen to issue a final rule that establishes a 
performance standard for processor-based train control systems, but 
does not require that they be installed. PTC systems can enhance the

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safety of railroad operations; the rule will help facilitate the 
establishment of such systems.

III. Regulatory Background

    Part 236 was last amended in 1984. At that time, signal and train 
control functions were performed principally through use of electrical 
circuits employing relays as the means of effecting system logic. This 
approach had proven itself capable of supporting a very high level of 
safety for over half a century. However, electronic controls were 
emerging on the scene, and several sections of the regulations were 
amended to take a more technology-neutral approach to the required 
functions (see Sec. Sec.  236.8, 236.51, 236.101, 236.205, 236.311, 
236.813a). This approach has fostered introduction of new, more cost 
effective technology while providing FRA with strong enforcement powers 
over systems that fail to work as intended in the field.
    Since that time, FRA has worked with railroads and suppliers to 
apply the principles embodied in the regulations to emerging technology 
and to identify and remedy initial weaknesses in some of the new 
products. As a result, thousands of interlocking controllers and other 
electronic applications are embedded in traditional signal systems. 
Further technological advances may provide additional opportunities to 
increase safety levels and achieve economic benefits as well. For 
instance, implementation of innovative PTC systems may employ new ways 
of detecting trains, establishing secure routes, and processing 
information. This presents a far greater challenge to both signal and 
train control system developers and FRA. This challenge involves 
retaining a corporate memory of the intricate logic associated with 
railway signaling, while daring to use whole new approaches to 
implement that logic--at the same time stretching the technology to 
address risk reduction opportunities that previously were not 
available. For FRA, the challenge is to continue to be prepared to make 
safety-based decisions regarding this new technology, without impairing 
the development of this field. Providing general standards for the 
development and implementation of products utilizing this new 
technology is necessary to facilitate realization of the potential of 
electronic control systems and for safety and efficiency.
    FRA has already used its safety authority to grant waivers and 
issue orders to support innovation in the field of train control 
technology. FRA has granted test waivers for the Union Pacific Railroad 
Company (UP)/Burlington Northern and Santa Fe Railway Company (BNSF) 
Positive Train Separation (PTS) project in the Pacific Northwest, the 
National Railroad Passenger Corporation (Amtrak) Incremental Train 
Control System (ITCS) in the State of Michigan, the CSX Transportation, 
Inc. (CSXT) Communication-Based Train Management (CBTM) project in 
South Carolina and Georgia, and the Alaska Railroad PTC project. On 
September 19, 1996 FRA granted conditional revenue demonstration 
authority for ITCS. In 1998, FRA issued a final order for the 
installation of the Advanced Civil Speed Enforcement System (ACSES) on 
the Northeast Corridor (63 FR 39343, Aug. 21, 1998). See also 64 FR 
54410, Oct. 6, 1999 (delaying effective date of such order).
    Although FRA expects to continue its support for these current 
projects, the need for controlling principles in this area has become 
patently obvious. This rulemaking has provided a forum for identifying 
and codifying those principles.

IV. RSAC

A. Overview

    In March 1996, FRA established the RSAC, which provides a forum for 
consensual rulemaking and program development. The Committee includes 
representation from all of the agency's major customer groups, 
including railroads, labor organizations, suppliers and manufacturers, 
and other interested parties. A list of member groups follows:

American Association of Private Railroad Car Owners (AARPCO)
American Association of State Highway & Transportation Officials 
(AASHTO)
American Public Transportation Association (APTA)
American Short Line and Regional Railroad Association (ASLRRA)
American Train Dispatchers Department/Brotherhood of Locomotive 
Engineers (ATDD/BLE)
Amtrak
Association of American Railroads (AAR)
Association of Railway Museums (ARM)
Association of State Rail Safety Managers (ASRSM)
Brotherhood of Locomotive Engineers (BLE)
Brotherhood of Maintenance of Way Employees (BMWE)
Brotherhood of Railroad Signalmen (BRS)
Federal Transit Administration (FTA)*
High Speed Ground Transportation Association
Hotel Employees & Restaurant Employees International Union
International Association of Machinists and Aerospace Workers
International Brotherhood of Boilermakers and Blacksmiths
International Brotherhood of Electrical Workers (IBEW)
Labor Council for Latin American Advancement (LCLAA)*
League of Railway Industry Women*
National Association of Railroad Passengers (NARP)
National Association of Railway Business Women*
National Conference of Firemen & Oilers
National Railroad Construction and Maintenance Association
National Transportation Safety Board (NTSB)*
Railway Progress Institute (RPI)
Safe Travel America
Secretaria de Communicaciones y Transporte*
Sheet Metal Workers International Association
Tourist Railway Association Inc.
Transport Canada*
Transport Workers Union of America (TWUA)
Transportation Communications International Union/BRC (TCIU/BRC)
United Transportation Union (UTU)

*Indicates associate membership.

When appropriate, FRA assigns a task to RSAC, and after consideration 
and debate, RSAC may accept or reject the task. If accepted, RSAC 
establishes a working group that possesses the appropriate expertise 
and representation of interests to develop recommendation] to FRA for 
action on the task. These recommendations are developed by consensus. 
The working group may establish one or more task forces or other 
subgroups to develop facts and options on a particular aspect of a 
given task. The task force or other subgroup reports for the working 
group. If a working group comes to consensus on recommendations for 
action, the package is presented to the RSAC for a vote. If the 
proposal is accepted by a simple majority of the RSAC, the proposal is 
formally recommended to FRA. FRA then determines what action to take on 
the recommendation. Because FRA staff has played an active role at the 
working group and subgroup levels in discussing the issues and options 
and in drafting the language of the consensus proposal and because the 
RSAC recommendation constitutes the consensus of some of the industry's 
leading experts on a given subject, FRA is often favorably inclined 
toward the RSAC recommendation. However, FRA is in no way bound to 
follow the recommendation and the agency exercises its independent 
judgement on whether the recommended rule achieves the agency's 
regulatory goal, is soundly supported, and is in accordance with policy 
and legal requirements. Often, FRA varies in some respects from the 
RSAC recommendation in developing the actual regulatory proposal. If 
the working group is unable to reach consensus on recommendations for

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action, FRA moves ahead to resolve the issue through traditional 
rulemaking proceedings.

B. The PTC Working Group

    On September 30, 1997, the RSAC accepted a task (No. 97-6) entitled 
``Standards for New Train Control Systems.'' The purpose of this task 
was defined as follows: ``To facilitate the implementation of software 
based signal and operating systems by discussing potential revisions to 
the Rules, Standards and Instructions (Part 236) to address processor-
based technology and communication-based operating architectures.'' The 
task called for the formation of a working group to include 
consideration of the following:
     Disarrangement of microprocessor-based interlockings;
     Performance standards for PTC systems at various levels of 
functionalities (safety-related capabilities); and
     Procedures for introduction and validation of new systems.

RSAC also accepted two other tasks related to PTC, task Nos. 97-4 and 
97-5. These tasks dealt primarily with issues related to the 
feasibility of implementation of PTC technology.
    FRA gratefully acknowledges the participation and leadership of 
representatives of the following organizations who served on the PTC 
Working Group (hereafter Working Group):

AAR, including members from
    BNSF
    Canadian National
    Consolidated Rail Corporation
    CSX
    Metra
    Norfolk Southern Railway Company
    UP
AASHTO
Amtrak
APTA
ASLRRA
ATDD/BLE
BLE
BMWE
BRS
FRA
High Speed Ground Transportation Association
IBEW
RPI
UTU

Staff from the National Transportation Safety Board and the Federal 
Transit Administration also participated in an advisory capacity.
    In order to efficiently accomplish the three tasks assigned to it 
involving PTC issues, the Working Group empowered two task forces to 
work concurrently: The Data and Implementation Task Force, which 
handled tasks 97-4 and 97-5, and the Standards Task Force, which 
handled task 97-6.
    The Data and Implementation Task Force finalized a report on the 
future of PTC systems and presented it, with the approval of RSAC, to 
the Administrator in September of 1999. Report of the Railroad Safety 
Advisory Committee to the Federal Railroad Administrator, 
``Implementation of Positive Train Control Systems'' (September 8, 
1999).
    The Working Group also employed several teams, comprised of 
representatives from RSAC member organizations, who provided invaluable 
assistance. An Operating Rules Team was charged with working to ensure 
that appropriate railroad operating rules are part of any PTC 
implementation process, and a Human Factors Team was charged with 
evaluating human factor aspects of PTC systems. Members of these teams 
serve on both the PTC Standards Task Force and the Data and 
Implementation Task Force, and additional team members were drawn from 
the railroad community.
    FRA staff and staff from the Volpe National Transportation Systems 
Center (the Volpe Center) worked with the Working Group and its 
subgroups. FRA responded to a consensus request from the Standards Task 
Force by contracting for assistance from the Center for Safety-Critical 
Systems at the University of Virginia.
    The NPRM describes the role the Standards Task Force played in 
developing its recommendations to the Working Group and RSAC, which 
were in turn recommended to FRA by RSAC and formed the basis for the 
proposed rule. The Standards Task Force ceased to meet and exist after 
publication of the NPRM. References to the Standards Task Force and 
Working Group are reiterated here to provide a historical perspective 
regarding development of the RSAC recommendations on which the NPRM was 
based. These points are discussed to show the origin of certain issues 
and the course of discussion on these issues at the Task Force and 
Working Group levels. We believe this helps illuminate the factors FRA 
weighed in making its regulatory decisions at the NPRM stage, and the 
logic behind those decisions, most of which are still embodied in this 
final rule.

V. Discussion of Alternatives Considered and the Rationale for the 
Option Selected

    As previously noted, RSAC recommended to FRA that it adopt the 
proposed rule recommended to RSAC by the Working Group. FRA concluded 
that the recommended proposed rule would satisfy its regulatory goals 
and issued an NPRM that tracked the RSAC recommendation on all major 
issues. Subsequent to the publication of the NPRM and the close of the 
comment period, informative discussions were had at the RSAC Working 
Group meetings regarding issues and concerns raised by written 
comments. These discussions contributed greatly to FRA's knowledge and 
understanding of the relevant subject matter, but, as discussed below, 
RSAC was ultimately unable to reach consensus on recommendations 
regarding the final rule.
    In this final rule, FRA has carried forward the basic principles 
and structure and in many cases the language of the proposed rule with 
few or no changes, as initially recommended by the RSAC at the NPRM 
stage. The text of the final rule is substantially different from the 
NPRM in only a few ways. First, FRA is adding a provision delineating 
the responsibilities of railroads and suppliers regarding software 
hazards; second, FRA is providing alternatives for the abbreviated risk 
assessment; third, FRA is providing criteria for adjustment to the base 
case where changes are planned in the subject operation's speed and 
density; fourth, FRA is adding a provision as notice that entities may 
be subject to criminal penalties in accordance with 49 U.S.C. 21311; 
and last, FRA is adding an appendix with a schedule of civil penalties. 
In addition, minor edits for improved clarity and consistency have been 
added. Each of these substantive changes will be addressed in the 
section-by-section analysis of the rule text to which it applies. 
However, given the failure of RSAC to reach consensus at the final rule 
stage, FRA has determined the contents of the final rule, without the 
benefit of a formal RSAC recommendation, based on the agency's best 
judgment (informed, in many cases, by the excellent discussion of the 
issues within the Working Group).

A. Performance Standards vs. Prescriptive Standards

    During early discussions in the advisory process, FRA noted that 
the existing ``Rules, Standards and Instructions'' (part 236) take a 
performance-oriented approach at the functional level, although--by 
virtue of the historical context in which they were initially 
prepared--they most often reference older technology. During the last 
decade and a half, this performance-oriented approach to specified 
functions has permitted the growth of electronic systems within signal 
and train control

[[Page 11056]]

systems without substantial regulatory change (albeit with growing 
ambiguity concerning the application of individual provisions to novel 
technical approaches). Wishing to maintain historical continuity and 
hasten preparation of a proposed and ultimately a final rule, FRA 
offered for consideration an initial redraft of part 236 that attempted 
a more technology-neutral approach to performance at the functional 
level, while also addressing PTC functions, as a possible starting 
point for the group's work.
    Carrier representatives found the FRA draft to be unduly 
constricting, and asked thatthe group pursue higher-level performance 
standards. Supplier and labor representatives agreed to this approach, 
and FRA endeavored to support the Standards Task Force in pursuing it.
    The group heard from representatives of the Research and Special 
Programs Administration, Federal Highway Administration's Office of 
Motor Carrier Safety (now Federal Motor Carrier Safety Administration), 
and APTA. FRA distributed a guidance document entitled ``Performance 
Standards: A Practical Guide to the Use of Performance Standards as a 
Regulatory Alternative,'' (Project on Alternative Regulatory 
Approaches, September 1981), a copy of which has been placed in the 
docket of this rulemaking.
    In brief overview, the term ``performance standard'' has been 
variously applied to describe many different forms of regulatory 
approaches that avoid design specifications and other prescriptive 
requirements, such as mandates that actions be taken in a particular 
sequence, or in a particular manner, by the regulated entity. At the 
most permissive extreme, a performance standard for a railroad 
operating system might specify an ``acceptable'' level of safety 
performance (e.g., number of fatalities per million train miles) and 
avoid any intervening action unless and until the performance of the 
regulated entity fell below that level. FRA believes that this type of 
approach would represent an abandonment of the agency's responsibility 
to promote safety, since it would necessarily assume optimum 
performance by the regulated entity (a condition not realized in 
practice) and would prevent helpful intervention until unacceptable 
consequences had already occurred. FRA has not sought to pursue this 
approach.
    The least permissive performance standards include such approaches 
as requiring that a metal skin on the front of a locomotive have 
penetration resistance equivalent to that of a given thickness of a 
specified steel. In this example, the choice of material is left to the 
designer, but the options are not extensive. See, e.g., Sec.  238.209.
    In the middle range of permissiveness, a performance standard might 
address acceptable performance parameters for a particular, mandated 
device, in lieu of a fixed physical description. For instance, FRA 
requirements for railroad tank cars carrying flammable compressed gas 
require the application of high temperature thermal protection that can 
be accomplished using a variety of materials, together with pressure 
relief valve capacity requirements adequate to permit safe evacuation 
and burn-off of the car's contents prior to catastrophic failure of the 
vessel in a fire environment (part 179, Appendix B (qualification test 
procedure)). This combination of regulatory requirements has been 
highly effective in preventing loss of life from violent detonation of 
tank cars involved in derailments (although compliance issues have been 
presented by disintegration of insulation blankets that could not be 
readily detected under the outer jacket of a car).
    Some of the safety statutes administered by FRA contain 
performance-based criteria. For instance, the Signal Inspection Act, as 
codified at 49 U.S.C. 20502(b), states:

    A railroad carrier may allow a signal system to be used on its 
railroad line only when the system, including its controlling and 
operating appurtenances * * * may be operated safely without 
unnecessary risk of personal injury.

However, recognizing the need to make a practical application of this 
broad statement, the law also requires that the system ``has been 
inspected and can meet any test prescribed under this chapter.'' What 
could otherwise be deemed a very broad performance standard is thus 
made more specific in practice.

B. Evaluation of Perfomance-Based Approach

    The NPRM identified a variety of considerations relevant to 
whether, and in what form, performance standards should be employed in 
this and other settings. After review of the public comments on the 
NPRM, FRA is satisfied that, as a general matter, the performance 
standard contained in the final rule should be suitable for this 
context. That is--
     The standard is stated as a practical goal;
     It will be enforceable;
     It will be usable by small entities;
     It can be shown to yield safety that is equivalent to that 
required under the existing Rules, Standards and Instructions (RS&I) 
issued by FRA's predecessor the Interstate Commerce Commission (ICC) 
and carried forward by FRA in part 236;
     Its cost is reasonable;
     It provides means of determining compliance before safety 
is endangered; and
     As adapted in this final rule, analytical techniques 
needed to verify compliance are available.
    This last point bears further mention. FRA expressed concern in the 
NPRM that a risk assessment technique, the Axiomatic Safety-Critical 
Assurance Process(ASACP), intended to provide an important toolset to 
establish compliance with the performance standard was still under 
development. Although that continued to be the case as FRA was 
preparing this final rule and submitting it for review and clearance, 
FRA has made appropriate changes to this final rule emphasizing FRA's 
conclusion that more than one type of risk assessment is acceptable.
    FRA had also identified several desirable criteria with respect to 
promulgating a performance standard specifically for processor-based 
signal and train control technologies: Simplicity, relevancy, 
reliability, cost, and objectivity.
    Simplicity: Although nothing about producing a safety-critical 
signal or train control system is inherently simple, the final rule is 
relatively simple and provides the railroads with a great deal of 
flexibility.
    Relevancy: Like the NPRM, the final rule focuses on the safety-
relevant characteristics of systems and emphasizes all relevant aspects 
of product performance.
    Reliability: This criterion could also be referred to as precision. 
That is, the standard should be reliable in that the test applied 
should yield similar results each time it is applied to the same 
subject matters. This criterion remains a concern in relation to the 
functioning of the final rule, but FRA has determined that the 
challenges presented should be manageable.
    Cost: FRA pointed out in the NPRM that demonstrating compliance 
with the standard should not be unduly expensive. In reviewing the 
comments and making adjustments to the final rule, FRA has structured a 
standard that is not unduly expensive.
    Objectivity: A completely objective standard would allow for 
compliance to be determined through scientific study or investigation. 
This is another dimension of enforceability. Like the NPRM, the final 
rule includes a number of provisions intended to ensure that

[[Page 11057]]

application of the standard will be demonstrably objective.

C. Advantages of a Performance-Based Standard; Consideration of 
Disadvantages

    This final rule presents the highest level performance requirements 
ever attempted by FRA. In the NPRM, FRA discussed at length both the 
reasons to pursue such a course and concerns perceived by the agency 
regarding its wisdom.
    Since issuance of the NPRM, FRA has continued its inquiries into 
the advantages and limitations of high-level performance standards and 
the current utility of available risk assessment techniques to 
determine compliance with such standards. See, e.g., Coglianese, Nash, 
and Olmstead, Performance-Based Regulation: Prospects and Limitations 
in Health, Safety, and Environmental Protection (Regulation Policy 
Program, John F. Kennedy School of Government, Harvard University 
2002). FRA has been impressed both by the potential power of 
performance standards to foster innovation and by the fact that most 
regulatory implementations of the concept have been layered on top of 
prescriptive standards rather than replacing them. That is, practice in 
most agencies with similar missions has focused on being ``risk 
informed'' rather than ``risk driven.'' The fundamental reason for this 
is the inherent difficulty of predicting safety outcomes in complex 
environments.
    FRA remains concerned that the performance-based approach of this 
final rule may not ensure progressive improvements in safety. Risk 
management practitioners typically set goals for incremental 
improvements in safety in connection with use of performance standards. 
By contrast, this final rule makes current risk levels the floor for 
future performance. However, if reductions in risk levels do not occur 
as part of the natural progression from application of the rule's 
performance based standards, the improvement in risk levels can be 
achieved by regulatory mandate. FRA refers in the final rule to the 
prerogative of the agency to order improvements in safety where they 
are supported by appropriate analysis.
    In the NPRM, FRA also expressed doubt regarding whether the 
relevant technical, scientific, and railroad signaling communities are 
fully prepared to support implementation of the proposed rule. Although 
commenters did not appear to question the fact that the field of 
safety-critical systems is relatively new and undergoing a process of 
maturation, they did question some of FRA's assertions. For instance, a 
major signal supplier noted that suppliers do provide quantitative 
information concerning life-cycle safety performance in the transit 
market. The same supplier stated that the concept of product validation 
is much better settled than suggested by FRA in the NPRM and questioned 
FRA's suggestion that quantifying risk with respect to electronic 
systems was somehow more difficult than with electro-mechanical 
systems. Notably, however, the supplier was addressing this topic from 
the context of design and production of systems utilizing traditional 
safety concepts. The same commenter noted that much more challenging 
issues associated with less conventional systems (including those 
relying upon complex commercial off-the-shelf hardware or software for 
which source code is not available to the designer and where changes 
may be introduced without notice).
    Commenters generally did not question the difficulty associated 
with assigning values to human factor risk, and FRA's consideration of 
the issues as informed by intervening discussions of the Working Group 
(including presentation and discussion of various risk assessment 
topics) has done nothing to call into question FRA's original concerns 
regarding the complexity of safety proofs at the system level, 
particularly where human factors or non-conventional electronic systems 
are involved.
    Neither did commenters effectively reassure FRA regarding the 
danger that risk assessment could become an ``after the fact'' 
justification for a system already constructed. This concern could be 
exacerbated by the difficulty of conducting risk assessments in 
parallel with product development against tight time deadlines. Under 
such circumstances, the tendency is to assign each subsystem of the 
electronic system a ``risk budget,'' after which the temptation to stay 
within budget could have the tendency to skew estimates. FRA has 
removed a sentence from the appendix on risk assessment that could be 
read to endorse this approach; but there is, of course, no reasonable 
way to prevent it from occurring. Rather, FRA will need to be alert to 
this procedure; and, where it is used, it may be appropriate to require 
a third party assessment of the verification and validation process 
that yielded the compliant estimates.

D. Analysis of Risk Associated With Train Control Technologies

    As reported in the NPRM, recognizing the need to advance the state 
of the art with respect to analysis of risk specifically associated 
with various methods of operations and train control technologies, the 
Standards Task Force established a team to support development of a 
ASCAP. At the request of the Standards Task Force, FRA engaged the 
University of Virginia (UVA) to develop the ASCAP model as a risk 
assessment ``toolkit'' for use in implementing the PTC rule then under 
development. The initial challenge for the ASCAP team and contractor 
was to describe the level of risk associated with the current method of 
operation on a CSXT line, which is operated without a signal system 
using direct traffic control system rules (the ``base case''). The 
first comparison case was to be the operations on the same line should 
a traffic control system be installed. The second comparison case was 
to be implementation of the proposed Communications Based Train 
Management (CBTM) system, an innovative technology that addresses the 
PTC core functions.
    As the effort progressed, the traffic control case was eliminated 
and the effort focused on CBTM. This ``dry run'' for ASCAP resulted in 
development of important elements of the technique, including a 
relatively sophisticated train management algorithm. The CBTM exercise 
was then suspended due to the need for the University to focus on the 
safety case for the Illinois DOT Project under contract to System 
Designer and Integrator for the North American Joint Positive Train 
Control Program (NAJPTC). When UVA last briefed the RSAC Working Group 
on this effort in March of 2003, it was clear that the method had been 
greatly enriched; however, neither the adjusted base case nor the PTC 
case had yet been finalized. Due to the difficulty of obtaining useful 
human factors data, that element of the analysis appeared to be the 
portion of the work still subject to review and potential redirection.
    FRA reiterates that the ASCAP approach appears to have significant 
value for distinguishing risk between the previous condition and 
proposed systems. However, in developing this final rule, FRA has 
necessarily taken notice of the fact that constructing the method has 
proved much more difficult than initially predicted; and nothing 
approaching validation of the method has yet been undertaken. As a 
result, the application of recognized alternative risk assessment 
methods used in other industries is anticipated. These traditional 
methods will be accepted on a case-by-case basis, after technical 
review by the Associate Administrator for Safety.

[[Page 11058]]

E. Choice of Type of Performance Standard

    FRA adopts the performance standard contained in the NPRM, which is 
basically that the new condition be at least as safe as the previous 
condition. In the preamble to the proposed rule, FRA acknowledged that 
this is a static level of safety.
    Following issuance of the NPRM, the agency focused further on the 
problem of how to characterize the base case. FRA noted that, in cases 
where no adjustment of the previous condition was necessary, the rule 
might actually result in uneven outcomes depending upon the level of 
safety on the particular railroad and particular territory. Very often 
the level of safety is affected significantly by intangibles such as 
specific provisions of the operating rules, training, degree of 
supervisory oversight, and degree of professionalism of the work force. 
A railroad with a good safety record could, in effect, be constrained 
in terms of future options by its own good performance. Such a railroad 
would likely have a commitment to continuous improvement, and FRA did 
not want to create the opportunity for safety to decline. On the other 
side of the ledger, it is a positive thing that safety would be 
improved through investments in signals or train control in an area 
where risk had been relatively higher; however, FRA did not want to 
``set the bar too high'' lest needed improvements be discouraged.
    FRA embraces this concept of progressive improvement and realizes 
that actual safety outcomes do differ, despite every attempt to 
maintain minimum standards. FRA notes that, in cases where adjustment 
of the base case is required, reliance on average numbers for similar 
territory may be required, which may have the effect of leveling the 
playing field over time.

F. Options for Demonstrating Compliance With the Performance Standard

    In the NPRM, FRA described a series of options for demonstrating 
compliance with the performance standard and explained that the option 
selected could be best described as a Bayesian belief network. A 
Bayesian Network is a special type of mathematical construct called an 
`` acyclic directed graph'' that represents relationships between 
logical propositions consisting of a set of assumptions called 
variables. A simple example of an ``acyclic directed graph'' is the 
elimination tree used in many sporting events. Each variable in the 
logical proposition is independent of other variables that it does not 
share a common parent with. The joint probability over all variables, 
which is the probability of the events represented by the graph, 
occurring is represented in terms of local probabilities associated 
with each of the individual variables. Its principal limitation is that 
it may not appear totally objective. It asks that the railroad 
demonstrate ``to a high degree of confidence,'' that the proposed 
product would result in no loss of safety. The railroad would be 
required to make this finding initially. The NPRM attempted to make it 
clear that, in any case where approval was required, FRA would 
determine the sufficiency of the safety case. However, the manner in 
which that would be done was not made clear, since the definition of 
``high degree of confidence'' embodied a ``reasonable decision-maker'' 
standard that would be employed to determine compliance, and the 
railroad had a duty (carried forward in this final rule) to make an 
initial determination that the safety case was sufficient.
    Since issuance of the NPRM, which pointed out the technical 
challenges associated with issues underlying administration of a 
performance standard, FRA has noted slow (albeit demonstrable) progress 
toward resolution of those issues. Accordingly, FRA is concerned that, 
given the subjectivity inherent in the ``reasonable decision maker'' 
finding (which would increase in proportion to the weight of the safety 
case derived from assumptions and judgments, as opposed to quantified 
empirical evidence), and given the range of decisions ``reasonable 
decision-makers'' might make, the proposed structure of the NPRM could 
prove problematic. In particular, FRA wishes to achieve consistency in 
outcomes for comparable Product Safety Plans (PSPs), promoting fairness 
for all parties and predictability in terms of what will be acceptable.
    FRA notes that most PSPs will be handled in accordance with the 
informational filing procedures, and in that context judgments by 
railroads will be accepted at face value if the necessary analysis has 
been completed and incorporated into the PSP. However, where FRA is 
faced with the need to make a decision whether to approve a PSP that is 
taken for review--given the degree of uncertainty associated with much 
of the underlying analysis associated with a complex processor-based 
system--it is important that FRA's judgment be applied. Other 
provisions of the proposed rule appear to anticipate that this will be 
done.
    Accordingly, in this final rule FRA makes clear that, in any case 
where approval is required, FRA will make the decision de novo, based 
upon the information provided within or accompanying the PSP and the 
criteria set forth in Sec.  236.913(g). The result of this change is 
that any judicial review of FRA's determination would focus on whether 
FRA came to a result compatible with that of a reasonable decision 
maker with the agency's expertise and knowledge of its own requirements 
(by law FRA may not act in an arbitrary or capricious manner), rather 
than whether the railroad acted as a reasonable decision maker. In any 
event, given the difficulty of the underlying analysis, it is important 
for safety and uniformity that suppliers and railroads anticipate the 
need to make a persuasive case to FRA that the standard is met. FRA 
also clarifies Sec.  236.909(b) with regard to the finding of 
sufficiency.
    The primary goal of the risk assessment required by this rule is to 
give an objective measure of the levels of safety risk involved for 
comparison purposes. As such, FRA believes the focus of the risk 
assessment ought to be the determination of relative risk levels, 
rather than absolute risk levels. Thus, like the proposed rule, the 
final rule attempts to emphasize the determination of relative risk.
    The Standards Task Force realized that risk assessments may be 
performed using a variety of methods, so its recommendation to the 
Working Group and the Working Group's recommendation to RSAC, in 
connection with the NPRM, proposed the creation of certain guidelines 
to be followed when conducting risk assessments. FRA feels that these 
guidelines, captured in Sec.  236.909(e) and Appendix B, adequately 
state the objectives and major considerations of any risk assessment it 
would expect to see submitted per subpart H. FRA also feels that these 
guidelines allow sufficient flexibility in the conduct of risk 
assessments, yet provide sufficient uniformity by helping to ensure 
final results are presented in familiar units of measurement.
    One of the major characteristics of a risk assessment is whether it 
is performed using qualitative methods or quantitative methods. 
Initially, the Standards Task Force considered proposing that only 
quantitative risk assessment methods be used to facilitate relative 
risk comparison. However, suppliers noted that certain risks, such as 
software coding errors, cannot be fairly or easily quantified, and that 
the industry practice is to assess such risks qualitatively. As 
suggested by RSAC at

[[Page 11059]]

the NPRM stage of the rulemaking process and as adopted by FRA, the 
final rule allows both quantitative and qualitative risk assessment 
methods to be used, as well as combinations of the two. FRA expects 
that qualitative methods should be used only where appropriate, and 
only when accompanied by an explanation as to why the particular risk 
cannot be fairly quantified. RSAC further recommended to FRA (in 
connection with the NPRM) that railroads/suppliers not be limited in 
the type of risk assessments they should be allowed to perform to 
demonstrate compliance with the minimum performance standard. FRA 
agrees with the philosophy stated here and feels that state of the art 
of risk assessment methods could potentially change more quickly than 
the regulatory process will allow, and not taking advantage of these 
innovations could slow the progress of implementation of safer signal 
and train control systems. Thus, FRA is allowing risk assessment 
methods not meeting the guidelines of this rule, so long as it can be 
demonstrated to the satisfaction of the FRA Associate Administrator for 
Safety that the risk assessment method used is suitable in the context 
of the particular product. FRA believes this determination is best left 
to the FRA Associate Administrator for Safety because the FRA retains 
authority to ultimately prevent implementation of a system whose PSP 
does not adequately demonstrate compliance with the performance 
standard under the final rule.
    Regardless of the risk assessment method used, FRA prefers the same 
method to be used for both previous condition (base case) calculations 
and calculations of risk associated with the proposed product. FRA 
prefers similar if not identical methods to be used so that meaningful 
comparisons can be made. However, the final rule does not mandate that 
identical methods be used in every case. FRA is aware that some types 
of risk are more amenable to measurement by using certain methods 
rather than others because of the type and amount of data available. 
For example, in almost all situations where advanced train control 
technology will be economically viable, safety risk data and accident 
histories will often be more abundant for the previous condition than 
for operation with the proposed product. The latter calculation will 
normally be based on supplier data about the product and modeling of 
how it is intended to be used on the railroad. Because FRA is 
interested in ensuring that each relative risk determination is 
accurate, the final rule does not outright mandate that the same 
assessment method be used. If a railroad does elect to use two 
different risk assessment methods, FRA will consider this as a factor 
for PSP approval (see Sec.  236.913(g)). Also, in such cases, when the 
margin of uncertainty has been inadequately described, FRA will be more 
likely to require an independent third party assessment (see Sec.  
236.913(h)).

VI. Proceedings to Date

    On August 10, 2001, FRA published the NPRM concerning the 
establishment of performance standards for development and use of 
Processor-Based Signal and Train Control systems (66 FR 42352). As 
noted above, the NPRM was based on the extensive work of the Standards 
Task Force and additional input from the entire PTC Working Group. The 
recommendations of the Working Group, which included those of the Task 
Force, were recommended by the full RSAC to FRA. Much of the 
information presented here was published in the NPRM. Since most 
readers will not have the benefit of consulting both the NPRM and the 
final rule together, FRA feels that republication of pertinent 
background and explanatory material in one document is appropriate.
    The publication of the NPRM engendered much response. FRA extended 
the deadline for written comments in response to specific requests for 
additional time, and to ensure that all commenters had an opportunity 
to fully develop their observations (66 FR 51362 ). FRA received a 
total of 27 comments to the NPRM which can be found in the public 
docket of the rulemaking. FRA did not receive a request for a hearing 
and did not hold a hearing.
    The comments ranged from observations regarding the historical 
accuracy of the origin of the practices now codified at part 236 and 
observations concerning the RSAC process to technical commentary 
regarding the risk assessment methodology proposed in the rule. The 
Working Group met December 4-6 of 2001 in San Antonio, Texas to 
consider comments that had been submitted as of that date. Additional 
comments were received after the initial Working Group meeting and have 
also been addressed in this notice. Although the later comments were 
received long after the deadline for comment submission, FRA has 
attempted to address those comments, as well.
    FRA found the discussions at the December 2001 meeting useful and 
extremely informative. Many of the commenters were present at the 
meeting and contributed to the discussion, of comments. Concerns raised 
by public comments were ultimately resolved by FRA, yet the resolutions 
were informed by insights obtained in the Working Group discussions. 
(Minutes of these discussions are in the docket of this rule.) The most 
challenging issues presented by commenters required additional research 
and analysis by FRA staff and contractors to the agency.
    As noted above, the discussions at San Antonio left open the 
question of when and how the base case should be adjusted. This issue 
was pursued by a Working Group team and addressed at the Working Group 
meeting of July 2003. No consensus on the subject was reached at the 
2003 Working Group meeting.
    At the July 2003 Working Group meeting, the Working Group did 
achieve consensus on several recommendations for resolution of other 
comments on the proposed rule and reported those recommendations to the 
full RSAC. During August of 2003, the RSAC reviewed the written report 
of the Working Group and voted by mail ballot. Those recommendations 
were circulated to the full RSAC for mail ballot, and responses were 
requested by August 14, 2003. A majority of RSAC members either voted 
to return the recommendations to the Working Group for reconsideration 
or non-concurred in the recommendations. Under RSAC procedures, the 
effect of this vote is to conclude RSAC action on the topic without an 
RSAC recommendation being to FRA. (Under RSAC procedures, any vote to 
return consensus recommendations to the working group must be 
unanimous, or the vote is scored as ``non-concur.'') In any event, 
FRA's schedule for completion of this rulemaking could not accommodate 
further months of deliberation on recommendations.
    FRA continued to refine the principles of this final rule in light 
of emerging experience with processor-based systems and risk assessment 
techniques until the time this final rule was submitted for review and 
clearance within the Executive Branch in September 2003. FRA has 
benefitted from the active discussion of the issues in this proceeding, 
including written comments and deliberations of the RSAC. Although the 
final resolution of the issues reflects insights gained in discussions 
of the Working Group and in the NPRM, FRA's final disposition of these 
issues is the responsibility of the agency and was based on its 
independent judgment.

[[Page 11060]]

    The agency is addressing general comments in this introductory 
portion of the preamble to the rule. However, the majority of the 
comments are addressed in the section-by-section analysis of the rule 
text to which they apply.

VII. Comments and Conclusions on General Issues

A. Background and RSAC Process

    One commenter wanted to clarify the history of the standards 
codified in part 236. This comment correctly identifies FRA's 
predecessor agency, the Interstate Commerce Commission (ICC), as having 
previously issued the same rules and noted that these regulations were 
based on the internal rules and practices of various railroads prior to 
World War II.
    Most commenters favorably regarded the RSAC process. One comment 
suggested continuing the work of the RSAC by developing sample Railroad 
Safety Program Plans (RSPPs) and PSPs. FRA has decided to continue the 
work of the Working Group by involving the members in monitoring the 
Illinois Project and serving as a sounding board for implementation of 
this rule and for other PTC efforts. Although the work of the group 
will continue, for reasons discussed later, FRA has determined that the 
agency will not be involved with the creation of sample documents. A 
reviewed RSPP draft for the Illinois Project is already available for 
consideration, and RSPPs are intended to be general documents that may 
take a similar form on most railroads. This final rule provides a 
detailed outline of required PSP elements, and the wide variety of 
products within the scope of the rule will require a range of 
adaptations in the format and content of PSPs. Other comments probed 
the membership of the PTC Working Group and inquired about the records 
kept for meetings and voting. Working Group minutes after publication 
of the NPRM are available in the public docket. Detailed voting records 
indicating the way in which various parties voted are not available, 
since a consensus process was utilized. The Working Group and task 
forces operated by unanimous consensus, whereby all participants 
supported the recommendations of the group. This process frequently 
entailed the presentation of issues and vigorous debate among the four 
stake holder groups. In many instances, stakeholders advocated opposing 
views, but were persuaded to either compromise or support the opposite 
view to attain consensus. The minutes reflect the nature and character 
of the debate demonstrating various options considered and key points 
impacting the consensus, when consensus was achieved by the group. The 
consensus product was then presented to the full RSAC which had the 
option of accepting or rejecting the Working Group's recommendations by 
a majority vote. The Working Group reached consensus on the 
recommendations comprising the NPRM, but could not reach consensus on 
recommendations for the final rule. Although ballots from the full RSAC 
are available to the public, these typically only show support or non-
concurrence for the final product, not positions on the individual 
issues that ultimately comprise the final rule. FRA has not kept and 
therefore has no avenue for providing the voting records on each issue. 
However, as previously noted, the text of the final rule differs in 
only a few major respects from the NPRM, which was based on the 
consensus recommendation of RSAC. In addition, FRA has attempted to 
note throughout the preamble issues where there were strong discussions 
and vigorous debate at the working group level.

B. The Performance-Based Approach

    FRA has decided to pursue a performance-based standard. FRA did not 
receive strong comments in support of or against its decision to use a 
performance-based approach. Comments seem to imply a need for a 
performance-based approach with some prescriptive elements, in lieu of 
a pure performance-based approach.

C. The Performance Standard--What Will Be the ``Base Case'' for 
Comparison?

    Among the comments on the risk assessment methodology was a filing 
from a noted signal expert who faulted the NPRM for, among other 
things, failing to recognize the capabilities of existing signal 
technology. The point was that it is incorrect to compare new 
technology with the rules for older technology (as in the proposed 
rule's construct for the ``previous condition''), to the extent the 
rules do not fully mirror that technology's inherent advantages. 
Rather, the commenter would have FRA recognize the actual capabilities 
of existing technology built to exceed existing minimum standards in 
terms of its actual functions. Any other course, it was implied, could 
lead to a reduction in safety. The commenter cited the example that cab 
signal systems respond to changes in track occupancy and route 
conditions almost immediately as an integral characteristic of their 
design, even though there is no explicit requirement that they do so. 
By contrast, communication-based technology may experience longer 
delays in response due to processing time and delays along the 
communications path. (Note: In FRA's experience, the extent of any 
difference in time for response to changed conditions may vary 
significantly from system to system, depending upon the overall 
architecture of the system, system priorities, communication protocols, 
communication capacity, and other factors.)
    Taking the commenter's point, FRA posed to the Working Group the 
need to recognize ``best practices'' under traditional signal design 
principles in constructing any adjusted base case. This resulted in 
alarm among some members, who viewed the notion as entirely open-ended 
and as posing the potential that the standard embodied in the rule 
might become increasingly strict over time. Such a case, they noted, 
could