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ITIS Phrase Tables, Draft [issued: 04-11-09]
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This is a draft document of the SAE ATIS committee, subject to change.
3.
Definitions
The definitions found in SAE J2540 are incorporated herein.
4.
Overview
This standard provides a set of phrases intended to describe traffic incident situations of interest to the
traveler. It is intended to be used in all ATIS message set standards, and is expected to be also used in a
number of other ITS industry standards as well. The sole exception to this is expected to be some very
limited bandwidth media devices (and example would be the RDS SubCarrier media) when only a single
phrase code can be allowed.
The specific rules of use can be found in the standard describing the message which uses these phrases.
This document defines the phrases themselves. The SAE J2540 document defines the use of the phrases in
practice, while each using standards defines the placement of the phrases in a message and any additional
restrictions which are needed. Thus, all uses of the phrases adhere to the rule set defined in SAE J2540, but
not all messages, or all media, allow support for the full set of possible features. Two specific examples are
worthy of note. SAE J2369, Revision 1.0 allows only a subset of the phrase table rules because this
standard was established before the more general rules of J2540. In the "ERM Message" of the TMDD
message set, some similar restrictions are used. For example, the insertion of free text is not allowed in
TMDD work. Consult the specific standard for complete rules and restrictions with regard to using the
phrases. As a general rule, other standards efforts are encouraged to use all of the defined ITIS phrase
categories so that they can make use of the ever increasing range of expression supported and so that
exchanges between the various standards are facilitated.
The phrases outlined in this document often also serve as a "prompting" text phrase in many traffic system
operator console designs, which when sent may involve further translations. Although this is beyond the
scope of this standard, using the various phrases to assist operators in correctly assembling a suitable
descriptive phrase is highly encouraged.
5.
Operating Concepts
This section outlines the use of the contents of the table messages and data element structures and provides
an overview of the operational exchange used in message transactions.
5.1
Use in General ITS messages
The basic concept of the ITIS phrases is that a collection of short textual phrases can be used the vast
majority of the time to express common traffic situations and can be easily coded and therefore
standardized as a sequence of numbers. Various uses of these numbers can then occur at the received end.
For the purposes of a preliminary operating concept, we will consider that they are simply reconstituted
into the same textual phrases at the receiver.
The purpose of this document is simply to establish the best possible set of such phrases. Ultimately, this
is an unobtainable goal, as local practices vary, the need for new phrases is always present, and other
maintenance issues arise. These are all dealt with in SAE J2540 and will not be considered here further.