(Note: The contents of draft D2.0 and draft D2.1 are identical; draft D2.0 includes strikeouts/underlines showing changes since draft D1.0 whereas draft D2.1 is a "clean" version.)

Alan Rumsey, WG2 chair, welcomed participants to this meeting of the IEEE Rail Transit Vehicle Interface Standards Committee, Working Group #2 (WG2), developing performance and functional requirements standards for Communications-Based Train Control (CBTC) systems. This meeting was hosted by APTA, and Alan Rumsey thanked Lou Sanders and the APTA staff for all of the meeting arrangements.

Bill Millar, APTA President, and Tony Kouneski, Vice President Member Services, also welcomed the meeting participants.

Alan Rumsey noted that a meeting of the CBTC Peer Group was being held after the WG2 meeting, on March 26, also in Washington. This meeting was being hosted by WMATA, and all transit agency representatives were invited to attend.

The minutes of the previous WG2 meeting, held in Melbourne Beach, Florida on January 21, 1998 were accepted as written.

Action items from the previous WG2 meeting were statused as follows:

Alan Rumsey advised that the revised PAR for the Working Group was still to be formally approved by the IEEE Standards Board at their next meeting, but no problems were anticipated.

[Post meeting note: PAR has now been approved by the IEEE Standards Board.]

The current WG2 mailing list consists of approximately 110 members and friends and was reviewed and updated by the meeting participants.

The FRA has proposed new Federal regulations that would require all trains operating on the north end of the Northeast Corridor (NEC) between Boston, Massachusetts and New York, New York, to be controlled by locomotives equipped to respond to a new advanced civil speed enforcement system (ACSES) in addition to the automatic train control (ATC) system that is currently required on the NEC.

The proposed speed enforcement system is not a continuous train control system, but rather an "add-on" to the existing ATC system. As such, the meeting participants could not identify any immediate impacts of this FRA notification of the work of the CBTC working group. John LaForce and John Vogler agreed to keep the working group appraised of any further developments in this area.

Alan Rumsey advised that all written comments received on draft versions of the proposed CBTC standard would be entered into the WG2 Comments Database (with the exception of minor typographical comments). A printout of the database will be tabled at each working group meeting. (It is not intended to make the database accessible on the web site). The printout would identify any new comments added to the database since the last meeting, and all comments that had been closed since the last meeting. (Comments that had been closed prior to the last meeting will be archived, and not included in the current printout. All comments will be retained, however, to provide an historical record of the workings of the group).

The meeting participants approved the use of the WG2 Comments Database as described.

The next WG2 meeting will be hosted by MUNI (Patty DeVlieg) and will be held in San Francisco on Wednesday, July 15, 1998. WG2 members and friends with be advised of specific details regarding meeting location etc. in due course.

A CBTC Peer Group meeting (open to transit agency representatives only) is planned for July 16/17, also at MUNI. The second day of this meeting will include a tour of the MUNI subway line to observe operation of the Alcatel ATCS system which is scheduled to be in operation on the line by that date.

Section 3.2 of draft D2.0/D2.1 ("Definition") was reviewed by the meeting participants, and current definitions were accepted as written with the following exceptions:

• the definition of "auxiliary wayside system" will be expanded to note that an auxiliary wayside system may also include trainborne equipment.
• the definitions of "emergency braking" and "maximum service braking", as defined by working group #5 (WG5), were questioned by a number of the meeting participants; participants were invited to submitted specific written comments/suggestions to the WG2 chair, who will then forward to WG5.
• the definition of "continuous train control system" will be deleted from the proposed standard (not considered necessary).
• since the term "unit" is defined as two or more vehicles semi-permanently connected together, the same term will not be used in section 5.3.1 to represent a "referenced" configuration of wayside and trainborne CBTC equipment.
• consideration will be given here, or elsewhere in the standard, to clarify what is intended by "high resolution train detection".

Section 3.2 will be updated in draft D3.0 to reflect the above agreements/comments.

Section 4.5 of draft D2.0/D2.1 ("Train operating modes") was reviewed by the meeting participants, and was generally accepted as written with the following comments:

• a note will be added to indicate that a future standard may address operation of trains without crews.
• the text will be revised to make it clear that in the context of this section, "trains" includes rail-mounted maintenance equipment.
• with respect to section 5.4.1.1, the text will be revised to clarify that ATO is an optional mode
• when the term "operations" is used here and elsewhere in the standard, the text will make it clear if the context refers to CBTC system operations, or the operations of the transit system.
• the terms "graceful degradation" and "graceful recovery" will be used instead of "fail-operational"; transit agencies will provide input as to their expectations with respect to various levels of degraded modes, to include definition of operating modes currently employed on their operating property.

Section 4.0 will be updated in draft D3.0 to reflect the above comments.

Section 5.1 of draft D2.0/D2.1 ("Headway requirements") was reviewed by the meeting participants and generally accepted as written with the following comments:

• paragraph on interfered headway will be revised to clarify intent
• impacts of multiple platform berthings will be noted

Section 5.1 will be updated in draft D3.0 to reflect the above comments.

Section 5.3 of draft D2.0/D2.1 ("System safety requirements") was reviewed by the meeting participants and generally accepted as written with minor comments.

Jim Hoelscher will review wording to ensure compatibility with the draft WG4 standard, to specifically include use of terms such as "hazard" and "risk".

Vic Grappone agreed to provide inputs regarding the proposed quantitative safety criteria, based on LIRR experience and expectations with respect to CBTC.

Section 5.3 will be updated in draft D3.0 to reflect comments received.

Section 5.4 of draft D2.0 ("System assurance requirements") was reviewed by the meeting participants, and the following comments were noted:

• section 5.4.1 will be revised to delete explicit reference to redundancy; system availability requirements should drive the architecture
• with reference to Mean Time to Repair, it will be clarified that this interval includes not only the time taken to replace an item of failed equipment, but also the time required to restore the equipment into operation; consideration will be given to defining a maximum repair/restore time, and also to defining 2^nd level repair times, i.e. time to repair a failed item of equipment once returned to the repair facility.
• meeting participants supported the general approach to system availability as contained in the discussion paper tabled by George Anagnostopoulos i.e. to relate CBTC equipment reliability to the on-time performance of the transit system, with CBTC system availability therefore being expressed in terms of [total revenue trips - revenue trips delayed (as a result of CBTC system failures)/total revenue trips].
• with respect to "revenue trips delayed", a delay below an authority-specified threshold would not be counted against the system availability criteria; for delays above this threshold, it was recognized that the longer the delay, the more significant the impact to passenger; the meeting participants therefore agreed that any measure of system availability should impose a greated penalty for longer delays.
• meeting participants acknowledged the practical difficulty of measuring CBTC system availability, i.e. establishing the CBTC system contribution to a revenue service delay, and it was suggested that the proposed standard attempt to also address this issue.
• requirements with respect to equipment "useful life" will be broken out into a separate subsection.

consideration will be given to including a subsection on system security requirements, particularly as related to the security and integrity of messages communicated over the RF data communications link.

Transit agencies agreed to provide further inputs to this section regarding their expectations with respect to reliability/availability/maintainability of CBTC systems.

George Anagnostopoulos agreed to update his discussion paper to include a delay value weighting factor in the determination of CBTC system availability.

Section 5.3 will be updated in draft D3.0 to reflect comments received.

The remaining sections of draft D2.0/D2.1were reviewed by the meeting participants, and the following comments were noted:

• each referenced publication currently listed in section 2 to be reviewed, and where appropriate, moved into Annex A (Bibliography).
• section 4.1 to explicitly reference "RF" data communications and to clarify "high resolution train location determination".
• tables (from existing industry specifications) will be added to section 5.5 to define environmental requirements for CBTC equipment - for further discussion.
• title of section 6.1.1 will be revised, as "train detection" implies train location determination only, and this section also addresses speed and travel direction determination.
• in section 6.1.8, "properly aligned" will be changed to "correctly berthed.
• Vic Grappone will provide inputs with respect to section 6.1.15 ("Grade crossing warning").
• Section 6.2.8 ("Trainborne passenger information system interfaces"), will be moved into the ATS section.

Meeting participants were invited to submit any additional comments in writing to the WG2 chair.

Draft D2.1 of the proposed standard will be updated to reflect comments received.

The following specific action items were recorded:

The schedule prior to the next WG2 will be as follows:

Dr. Alan F. Rumsey

Chair, WG2