A policy statement reflecting the committee's adopted positions on definitions is given below:

 It is committee policy to use IEEE Dictionary definitions if at all possible. Further, once any definition has been balloted and accepted for use in any standard sponsored by the IEEE Rail Transit Vehicle Interface Standards Committee it shall be binding for all other standards sponsored by the committee unless it can be shown to be clearly inappropriate.

If neither the IEEE Dictionary nor a RTVISC balloted standard provides a suitable definition, then the American Society of Mechanical Engineers Lexicon should be consulted for a suitable definition..

Next, standards sponsored by the ASME Rail Transit Standards Committee should be consulted. Definitions which have been  balloted and accepted for any standard sponsored by the ASME Rail Transit Standards Committee shall be also binding for all IEEE RTVISC standards unless there is a different existing IEEE definition or they  can be shown to be clearly inapplicable. 

If none of these sources produce a suitable definition,  the  TRB Glossary should be consulted .  It should be noted that  ASME and  TRB Glossary definitions are not presently IEEE definitions. Thus, they should be provided in the definitions section of the IEEE standard so they can be balloted and adopted as an IEEE definition.

Only when all of the above approaches has failed should a working group coin its own original definition. Since it is intended that all working groups of both IEEE RTVISC and ASME RTSC use common definitions,  Working group chairs should be careful when reviewing standards prepared by other working groups, to be sure the other group's definitions will be suitable for their standard also.

Paul Jamieson chairs the Definitions working group for both the IEEE RTVISC and the ASME RTSC and maintains a database with all definitions which can be downloaded from our website at


 IEEE Dictionary is available at the website

 Definitions adopted by the IEEE Rail Transit Vehicle Interfaces Standards Committee but not yet in the IEEE dictionary are kept at our committee website at

 "Safety Codes and Standards  Lexicon", January 2002, American Society of Mechanical Engineers

 "Urban Public Transportation Glossary",  Transportation Research Board, National Research Council, Benita H. Gray, Editor, 1989