[Federal Register: September 11, 2007 (Volume 72, Number 175)]
[Notices]
[Page 51896-51898]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr11se07-130]
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DEPARTMENT OF TRANSPORTATION
Federal Railroad Administration
Electronic Remote Authority Delivery Systems
AGENCY: Federal Railroad Administration (FRA), Department of
Transportation (DOT).
ACTION: Notice of interpretation.
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SUMMARY: FRA is issuing this notice of interpretation to inform
interested parties of its position regarding the implementation of
digital electronic remote authority delivery systems that permit
authorized users to electronically request, obtain, and release
authorities to occupy controlled tracks. These activities are
classified as safety-critical functions, and may interact with the
functions of train control systems and dispatching procedures.
Depending on the functionality and complexity of these systems,
railroads seeking to implement digital electronic remote authority
systems may be required to comply with Title 49 of the Code of Federal
Regulations (CFR) Part 236, Subpart H (Subpart H). This notice
classifies digital electronic authority delivery systems based on their
functionality and identifies categories of systems that are subject to
compliance with the requirements of Subpart H.
ADDRESSES: You may submit comments to Thomas McFarlin, Staff Director,
Signal and Train Control Division, or Olga Cataldi, Senior Electronic
Engineer, FRA Office of Safety Assurance and Compliance, by facsimile
(202-493-6216) or e-mail (thomas.mcfarlin@dot.gov) or
olga.cataldi@dot.gov). Comments may also be submitted to Kathy
Shelton, FRA Office of Chief Counsel, by facsimile (202-493-6068) or e-
mail (kathryn.shelton@dot.gov).
FOR FURTHER INFORMATION CONTACT: Thomas McFarlin, Staff Director,
Signal and Train Control Division, Office of Safety Assurance and
Compliance, FRA, 1120 Vermont Avenue, NW., Washington, DC, 20590
(telephone: (202) 493-6203), e-mail (thomas.mcfarlin@dot.gov); Olga
Cataldi, Senior Electronic Engineer, Office of Safety Assurance and
Compliance, FRA, 1120 Vermont Avenue, NW., Washington, DC, 20590
(telephone: (202) 493-6321), e-mail (olga.cataldi@dot.gov); or Kathy
Shelton, Office of Chief Counsel, FRA, 1120 Vermont Avenue, NW.,
Washington, DC 20590 (telephone: (202) 493-6063), e-mail
kathryn.shelton@dot.gov).
SUPPLEMENTARY INFORMATION:
Background
With technical advances and the wide availability of wireless
communication technology, a number of Class I and short line railroads
have been developing and, for the past several years, implementing a
variety of software-based applications for the electronic delivery of
digital track authorities to roadway workers. Software-based digital
communication between railroad workers and the dispatch center has
proven to be an effective alternative to voice communication with the
dispatcher via radio. Digital communications may potentially result in
significant increases in safety by eliminating delivery or read back
errors associated with voice communications. Digital communications may
also increase the effectiveness of railroad operations and track
maintenance resources utilization by significantly decreasing the time
associated with obtaining and releasing track authorities. These
potential operational and safety benefits are prompting railroads to
extend the use of wireless data communication to digital transmission
of track warrants to trains. Further, railroads are seeking to extend
the functionalities associated with the digital communication of
authorities to roadway workers and train crews to include the auto-
generation and issuance of authorities, excluding any involvement of
the dispatcher.
The regulations contained in 49 CFR Part 214, Subpart C, which
currently govern the delivery of authorities for exclusive track
occupancy to roadway workers, do not specifically address digital
communication between the dispatcher and the employee in charge.
Currently, 49 CFR 214.321(a)(1) requires that all authorities issued to
a roadway worker in charge be given by the dispatcher or control
operator who controls train movement on that track.
The digital delivery of movement authorities to train crews is
addressed in 49 CFR Part 236, Subpart H. This set of regulations
prescribes the minimum safety standards for the development and
operation of processor-based signal and train control systems. As
stated in the preamble to Subpart H, FRA purposely left the term
``train control'' undefined, as advances in technology supporting these
systems would make any definition of the term ``train control'', or any
list of train control systems and associated features, ``undoubtedly
outdated'' in a relatively short period of time. See 70 FR 11052,
11066. Therefore, the requirements contained in Subpart H apply to
``safety-critical products'', which include systems that provide
safety-relevant information on which crews are expected to rely. See 49
CFR 236.901. However, FRA emphasized in the preamble to the rule that
``[o]ther systems providing safety-relevant information on which crews
are expected to rely will also fall within this term''. See 70 FR
11052, 11066. In regard to dispatching systems, a centralized computer-
aided train dispatching system being a part of an ``office system'' may
also be subject to Subpart H compliance, if ``it performs safety-
critical functions within, or affects the safety performance of, a new
or next generation train control system.'' See 49 CFR 236.911(c).
FRA recognizes that its current regulations do not clearly address
the auto-generation and digital communication of authorities to roadway
workers and locomotive engineers. FRA is currently taking measures to
augment existing regulations to more clearly address these
functionalities. For example, FRA, with the participation of the
Railroad Safety Advisory Committee, has explored appropriate conditions
for the digital transmission of authority to a roadway worker in
charge. In light of these discussions, FRA expects to include specific
concepts in a notice of proposed rulemaking for revision of 49 CFR Part
214, Subpart C. Further, FRA has been in discussion with the
Association of American Railroads regarding the need for general
standards to ensure the effectiveness and security of wireless
communications particularly
[[Page 51897]]
in the field of train control. Pending the issuance of regulations and
other actions in this area, FRA believes that it is both necessary and
appropriate to clarify the existing regulatory requirements applicable
to the auto-generation and digital delivery of authorities. The
following discussion is intended to provide that clarification.
Classification of Digital Electronic Remote Authority Delivery Systems
Software-based digital electronic remote authority delivery systems
can be classified based on their purpose, and the level of dispatcher
involvement as follows:
By purpose:
Roadway Worker Protection (RWP) systems (deliver track
occupancy authorities to a roadway worker in charge).
Remote Authority systems (deliver track occupancy
authorities to a roadway worker in charge and movement authorities to a
train crew).
By dispatcher's role:
Dispatcher generated (or dispatcher confirmed) authorities
Automatically generated authorities (these authorities may
be generated by the system itself, by a computer-aided train
dispatching system (CAD), or as part of a positive train control
system).
Remote Authority and Roadway Worker Protection systems can both be
used in signaled and non-signaled (dark) territories. These systems can
operate as either an autonomous dispatching-type system or as an
overlay to an existing method of operation. Based on the classification
given above, FRA has identified four distinct categories of digital
electronic remote authority delivery system functionalities:
1. Electronic transmission of authorities to roadway workers with
dispatcher's electronic confirmation;
2. Electronic transmission of authorities to train crews with
dispatcher's electronic confirmation;
3. Automatic generation and electronic transmission of the
authorities to roadway workers without dispatcher's involvement; or,
4. Automatic generation and electronic transmission of the
authorities to train crews without dispatcher's involvement.
While FRA fully supports the railroad industry's desire to
implement digital electronic remote authority delivery systems, FRA
also believes that to the extent such systems execute the necessary
logic to generate valid mandatory directives or roadway work
authorities, they are functionally forms of train control subject to
Subpart H. Further, digital pathways embedded in conventional signal
and train control systems, including communication-based train control
systems, are relevant subsystems deserving of consideration within the
context of Subpart H review. In the event of malfunction of any of
these types of systems, FRA would expect each employing railroad to
have operating rules in place that address reversion to voice or
written delivery of authorities by the dispatcher, consistent with any
applicable existing regulations.
The following discussion provides clarification on the
applicability of FRA regulatory requirements to each category of
digital electronic remote authority delivery systems.
Systems Performing Electronic Transmission of Authorities to Roadway
Workers With Dispatcher's Electronic Confirmation
The software-based application (or processor-based system) belongs
to this category if:
1. It serves as an autonomous office (dispatching) system in the
absence of a CAD system, or as an auxiliary system interfaced with an
existing CAD system, and is used exclusively for issuing authorities to
roadway workers to occupy controlled tracks;
2. It allows the employee in charge to request, obtain, and release
the authority to occupy a controlled track through wireless digital
communication with the dispatcher or control operator in charge of the
track;
3. Upon receipt of an electronically transmitted request from a
roadway worker to occupy track, the authority is generated by the
dispatcher or automatically by the application system (or by CAD) and
is electronically transmitted by the application system accompanied by
electronic confirmation of the dispatcher;
4. The dispatcher holds ultimate responsibility for the proper
issuance of authority to roadway workers and for maintaining proper
records of track occupancy by other authorized users; and,
5. The system server retains electronic records of roadway workers'
requests for authority and dispatcher's entries of all authority
granted by the dispatcher, including those issued to trains.
Such systems perform functions described in 49 CFR Part 214,
although that part currently does not address means of authority
delivery. These systems are not, however, subject to Subpart H because
they only provide electronic transmission of track occupancy authority.
The generation and release of the authority remains the responsibility
of the dispatcher, as currently required by 49 CFR 214.321(a). Once the
revision of Part 214 is completed, these systems may be subject to new
requirements regarding electronic delivery of authorities to roadway
workers in charge (related to security and authentication of the
digital transmission).
Systems Performing Electronic Transmission of Authorities to Trains
With Dispatcher's Electronic Confirmation
The definition of this category of processor-based applications (or
computer-based systems) coincides with the definition given above for
RWP systems, except the delivery of authority is extended to trains.
FRA has determined that the electronic delivery of movement
authority to trains is a safety-critical function pertaining to train
control systems. If the dispatcher is involved in the process of
generating the authority or is confirming the CAD system-generated
authority, and the closed-loop communication occurs between the
dispatcher and train crew, FRA recognizes that the regulatory
requirements for systems delivering authorities to trains should be the
same as for those delivering authorities to roadway workers. FRA
further recognizes that, if the system includes functions related to
commanding or warning crews based on changing field conditions (e.g.,
in the same way a cab signal would ``drop'' if a circuit were
deenergized by equipment rolling out on the main line), then the system
is a train control application.
FRA utilizes the following criteria in determining the
applicability of Subpart H to systems of this category:
1. If the content of electronic messages transmitted to a train
crew are limited exclusively to movement authorities and other
mandatory directives, the application system is exempt from compliance
with Subpart H.
2. If the content of electronic messages transmitted to a train
crew, in addition to movement authorities and other mandatory
directives, contain warning or other enforcement commands impacting
train handling, the application system must comply with Subpart H.
3. If the communication subsystem embedded in any new train control
system is an integral part of that system, it is subject to Subpart H
requirements.
FRA encourages railroads to arrange digital systems which
communicate safety-critical information so that security of the
messages is maintained and authentication of those issuing and
[[Page 51898]]
acknowledging mandatory directives is established. Although use of
digital transmission has the advantage of accuracy (avoidance of
misunderstandings) and efficiency, insecure transmissions and lack of
proper authentication could introduce new risks. FRA expects that, as
this technology fully matures, industry standards will address these
needs even more suitably than at present within an interoperable
framework.
If Subpart H is applicable, the railroad shall submit an RSPP and
PSP required by 49 CFR 236.905 and 236.907.
Systems Performing Automatic Generation and Electronic Transmission of
the Authorities to Roadway Workers Without Dispatcher's Involvement
The processor-based application (or computer-based system) belongs
to this category if:
1. It serves as an autonomous office (dispatching) system, in the
absence of a CAD system, or as an auxiliary system interfaced or
integrated with an existing CAD system, and is used exclusively for
issuing authorities to roadway workers to occupy controlled tracks;
2. It allows the employee in charge to request, obtain, and release
the authority to occupy a controlled track through wireless digital
communication without the dispatcher's concurrence;
3. Upon receipt of an electronically transmitted request from a
roadway worker to occupy track, the authority is generated
automatically by the CAD system (or application system) and is
electronically transmitted by the application system without the
dispatcher's concurrence; and
4. The system server retains electronic records of roadway workers'
requests for authority and all granted authorities, including those
issued to trains.
Such systems are subject to compliance with Subpart H. The delivery
of track occupancy authority to roadway workers without the
dispatcher's involvement is considered a safety-critical function in
the same way that control of train movements is safety-critical. This
constitutes a basis for these systems to comply with Subpart H
requirements. Railroads shall submit an RSPP and PSP in accordance with
49 CFR 236.905 and 236.907 prior to implementing any such system.
Relief is also required from the requirements of Part 214, Subpart C,
related to dispatcher involvement in the issuance of roadway work
authorities.
Systems Performing Automatic Generation and Digital Transmission of
Authorities to Trains Without Dispatcher's Involvement
The definition of this category of processor-based applications (or
computer-based systems) coincides with the definition given in a
previous section for RWP systems, except that the delivery of
authorities is extended to trains.
Systems of this category are subject to compliance with Subpart H
because the delivery of track occupancy authority to roadway workers
and trains without dispatcher involvement is considered a safety-
critical function of a train control system. Therefore, railroads shall
submit an RSPP and PSP in accordance with 49 CFR 236.905 and 236.907
prior to implementing any such system.
Those interested in implementing systems that automatically
generate mandatory directives, roadway work authorities, or other
instructions or commands (executed by persons or equipment) bearing
directly on the safety of train operations, are respectfully referred
to Appendix C of 49 CFR Part 236, which outlines safety assurance
criteria and processes that are relevant to such an undertaking.
FRA seeks comments on this notice from interested parties. Please
refer to the Addresses section for additional information regarding the
submission of comments.
Issued in Washington, DC on September 4, 2007.
Jo Strang,
Associate Administrator for Safety.
[FR Doc. E7-17800 Filed 9-10-07; 8:45 am]
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