Alan Rumsey, WG2 chair, welcomed participants to this meeting of WG2, developing performance and functional requirements standards for Communications-Based Train Control (CBTC) systems. This meeting was hosted by the Volpe Center, and Alan Rumsey thanked George Anagnostopoulos for all of the meeting arrangements.

Alan Rumsey noted that a meeting of the CBTC Peer Group had been held the previous day, September 29, at the MBTA. Minutes of this meeting would be posted on the web site (www.tsd.org), once approved by the Peer Group.

Alan Rumsey advised that he presented a paper on North America initiatives on CBTC standardization at a conference in Lisbon, Portugal, on September 3, 1998 (Comprail ’98). This paper has also been posted on the web site, www.tsd.org.

Alan Rumsey advised that the Third International Conference on Communications Based Train Control (co-sponsored by Railway Age and De Leuw, Cather) would be held in Washington D.C. on May 11/12, 1999.

Lou Sanders advised that the 1999 APTA Rail Conference would be held at the end of May, 1999 in Toronto, Canada and would be a combined APTA/UITP/CUTA meeting.

Tom McGean briefed the group on the RTVISC meeting held in St. Louis on September 16/17, 1998. The next meeting of the full committee will be held on January 25/26, 1999 at the offices of Parsons Brinkerhof in Los Angeles.

Alan Rumsey provide a summary of WG2 status, and highlighted the key changes that had been introduced in the latest draft of the WG2 standard since the last WG2 meeting.

Alan Rumsey advised that is was still the group’s target to be in a position to ballot the CBTC performance and functional requirements standard early in 1999, and as such it was important for the group to reach closure on the various open issues.

Alan Rumsey advised that the current WG2 mailing list consists of approximately 100 active members and friends. The current mailing list was circulated, reviewed and updated by the meeting participants.

Alan Rumsey advised that all written comments received on draft versions of the proposed CBTC standard were being entered into the WG2 Comments Database (with the exception of minor typographical comments). A printout of the database was tabled and reviewed by the meeting participants. The printout identified all comments that had been open at the last meeting as well as new comments that had been added to the database since the last meeting. (Comments that had been closed prior to the last meeting have been archived, and were not included in the current printout. All comments are being retained, however, to provide an historical record of the workings of the group).

In summary, Alan Rumsey advised that approximately 300 written comments had been received to date of which approximately 270 had been addressed and were considered closed.

The next WG2 meeting will be held on December 8, 1998 and will be hosted by SEPTA in Philadelphia.

The minutes of the previous WG2 meeting, held at MUNI, San Francisco on July 15, 1998 were accepted as written.

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

The full Rail Transit Vehicle Interface Standards Committee has approved a recommendation from WG2 that it form a ballot group from within the WG2 membership, with interested members of the RTVISC, who are not currently members of WG2, also invited to be included within the ballot group.

The WG2 membership consist of "Producers" (suppliers, and consultants who receive the bulk of their income from suppliers), "Consumers" (transit agencies, and consultants who receive the bulk of their income from transit agencies), and "General Industry" (e.g. government and university representatives). No more than 50% of the Ballot Group can be drawn from any one of these three groups. In addition, there can be no more than two members from any one organization. Finally, participation on the WG2 Ballot Group, requires membership of the IEEE, as well as membership of the IEEE Standards Association (IEEE-SA).

Alan Rumsey advised that Annex C of draft D4.0 of the proposed standard ("Typical CBTC parameters") reflects all inputs received to date. Suppliers who had not yet provided inputs were encourage to do so. (Lack of time prevented a review of this Annex at this meeting.)

Alan Rumsey advised that Section 3.2 of draft D4.0 of the proposed standard ("Definitions") reflects all agreements reached at the last WG2 meeting, to include a revised definition for "movement authority", the addition of a "note" to the definition of "automatic train supervision (ATS)", and a new definition for "safe braking model".

The definition of a safe braking model was reviewed at this meeting and revised as follows:

"An analytical representation of a train’s performance while decelerating to a complete stop, allowing for a combination of worst-case influencing factors and failure scenarios. A CBTC equipped train will stop in a distance equal to or less than that guaranteed by the safe braking model."

Alan Rumsey advised that a number of definitions that had originated from WG5 have since been revised in response to ballot comments on the WG5 standard, and these revised definitions will be incorporated in the next draft of the WG2 standard.

Additional definitions may be added following a line-by-line review of the draft standard, prior to balloting.

With respect to the action item that transit agencies were to provide input as to their expectations regarding various levels of degraded modes, to include definition of operating modes currently employed on their operating property, additional responses had been received from Fred Childs (PATH) and Errol Taylor (BART). This action was considered closed.

In general, Section 4 of the draft standard is now considered "ballot ready". Minor changes were suggested to section 4.5 (to clarify that mixed mode operations includes simultaneous operation of both equipped as well as unequipped trains within CBTC territory), to section 4.5.2 (to improve readability), and to section 4.6.2 (to clarify that indications to the train operator may not be required if the transition between CBTC territory and non-CBTC territory is operational transparent to the train operator).

Alan Rumsey advised that major revisions had been made to Section 5.3 of draft D4.0 of the proposed standard ("System safety requirements") to reflect inputs received on the previous draft. Table 1 had been deleted, and much of the generic safety program related text had also deleted on the basis that this material is already better covered in existing standards. The draft section now has more emphasis on specific hazards to be prevented by CBTC systems, and specific CBTC vital functions. Revised section was reviewed later in the meeting. (See item 4.0 below).

No addition inputs have been received to date on section 6.1.15 ("Grade crossing warning"), and as such this action item will remain open. All WG2 members were invited to provide inputs to this section.

Alan Rumsey advised that major revisions had also been made to Section 5.4 of draft D4.0 of the proposed standard ("System assurance requirements"), to reflect comments received at the last WG2 meeting. As with the safety section, much of the generic availability/reliability/maintainability program related text has been deleted with more emphasis now on specific characteristics of CBTC systems to achieve desired improvements in signaling system availability. Revised section was reviewed later in the meeting. (See item 5.0 below).

The action item to provide a worked example of how the CBTC system contribution to passenger service delays could be measured in practice had not been completed in time for this meeting and remains open.

Marty Lukes (WMATA) had provided input on requirements for work train protection and work zone protection.

Alan Rumsey advised that a number of revisions had been made to Section 6.1 of draft D4.0 ("ATP functional requirements") based on agreements at the last WG2 meeting, of which the most significant is the addition of a new section on safe braking model. Revised section was reviewed later in the meeting. (See item 7.0 below).

Alan Rumsey advised that the remaining sections of draft D4.0 of the proposed standard had attempted to respond to all other comments received at the last WG2 meeting.

This section was reviewed in detail by the group, with the following agreements:

Section 5.3 will be updated in draft D5.0 to incorporate the above agreements.

Omar Rezzoug (Matra) gave a presentation on system availability requirements from a supplier’s perspective and noted that the following requirements needed to be specified in order for a supplier to propose an attractive system at minimum cost:

i) a formula for defining system availability

ii) a description of how system availability will be measured

iii) the target system availability to be achieved

iv) penalties associated with non-achievement of the system availability target

v) acceptance criteria for demonstrating achievement of the system availability target

An Excel-based model was demonstrated which calculated system availability estimates based on equipment failure rates and other factors such as fleet size and maintenance crew availability.

The system availability section was reviewed in detail by WG2, against the above background, with the following agreements:

Section 5.4 will be updated in draft D5.0 to incorporate the above agreements, and other meeting comments.

The environmental requirements for trainborne CBTC equipment are being defined by Working Group #8, and the WG8 draft standard (P1478) will be referenced by the WG2 standard.

It was agreed that the WG2 standard should continue to attempt to define environmental requirements for CBTC wayside equipment, based on the AAR Signal Manual and ATCS specifications. Jeff Eilenberg (LSTS) undertook to update section 5.5 accordingly.

Section 6.1 of draft D4.0 of the proposed standard was reviewed on a subsection-by-subsection basis, and the following comments were noted:

• ability to enter into an occupied track section (for example, at reduced speed), for failure recovery purposes.
• ability to reverse travel following station overshoot

c) "enable" in section 6.1.3 e) will be changed to "allow".

There was significant discussion on section 6.1.11 (route interlocking protection). It was agreed that the primary intent of this section was to address CBTC/interlocking functional interfaces, and to identify the impact of CBTC on basic interlocking functions. For example, with respect to approach locking, since the CBTC can determine the location and speed of a train in a vital fashion, it is no longer necessary to "run time", and the CBTC system can release the approach lock as soon as it is verify that the movement authority limit is set prior to the interlocking and that the train has come to a stop, or is capable of coming to a stop, prior to the interlocking. Errol Taylor (BART) agreed to draft a re-write of this section based on the meeting discussions.

Section 6.1 will be updated in draft D5.0 to incorporate the above agreements, and other meeting comments.

There was insufficient time to review section 6.2 of draft D4.0 of the proposed standard and this agenda item was therefore deferred to a future WG2 meeting.

The following specific action items were recorded:

The objective of the next meeting will be to finalize sections 5.3 (safety), 5.4 (availability) and 6.1 (ATP functions) and commence reviews of Annex C, section 5.5 (environmental) and sections 6.2/6.3 (ATO and ATS functions).

Draft D5.0 of the proposed standard will be issued at least two weeks prior to the next WG2 meeting.

Alan Rumsey closed the meeting thanking the working group participants for their attendance and active involvement in the various discussions, and again thanking the Volpe Center for hosting the meeting.

Minutes prepared by: Dr. Alan F. Rumsey, Chair, WG2