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ITIS Phrase Tables, Draft [issued: 04-11-09]
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221 -
This is a draft document of the SAE ATIS committee, subject to change.
8.4
Encoding Expressions of Distance
Many sign patterns have an optional expression of some distance or length from the sign point to some
other location. The pattern used for such expressions shall be:
<optional distance, value, units> or in expanded detail:
<optional direction or arrow><optional numerical value><optional units>
The direction or arrow can be a simple keyword (often taken from the MUTCD-locations category) such as
ahead, left, next signal, next stop, etc. The numerical value shall follow the rules established for numbers.
The units denotes what system of units is to be used (miles is presumed if this code is absent).
In constructing a sign using these patterns the following rules shall be observed:
Any named object in the expression shall follow the rules for encoding proper names.
Expressions with more than one proper name shall separate each name with the code words “and”
or “or” as needed.
In compound signs the expression of distance should come at the end of the sign, after all other
descriptive items.
The units term shall be present only when it is preceded by a numerical value.
The units of distance shall be presumed to be in miles if no units phrase is present.
Examples of proper encoding distance values:
Value to be expressed
Preferred Encoding
Byte Sequence
Stop Ahead
stop, ahead
12294, 13569
5 Miles
n5, miles
12549, 8712
West US Route 66 ahead 2 miles
west, route, n66, ahead, n2, miles
8001, 11779, 12610,
13569, 12546, 8712
I-5 left lane ¼ mile
interstate, n5, left lane, n1-4th, mile
11781, 12549, 8195,
11524, 8711
Weigh Station 1000 feet
weigh station, ahead, n1000, feet
11792, 13569, 11545, 8710
Left Lane Ends, ¾ mile
left lane ends, n3-4th, mile
8195, 13583, 11527, 8711