The table below lists the common acronyms used throughout this document and their meaning.
|CF||The Current Flow for the location. Current Flow is comprised of several attributes that describe how traffic is moving at location.|
|CN||The Confidence attribute, which is a number between 0.0 and 1.0 indicating the percentage of real time data included in the speed calculation. |
To only report speeds where real time data is available, we recommend that you include speeds with a confidence greater than 0.7 CN and include road closures with a value = -1.0 CN
|FF||The free flow speed on a particular stretch of road|
|FI||The entry for each flow item in the specified direction|
|FIS||A list of flow items (FI), one list for each direction of the roadway (RW). (1-many) |
The FI in each FIS section is guaranteed to be contiguous and in the order of the driving direction. If there is a break in continuity on an RW, then there are 2 or more FIS elements in the RW.
|JF||A number between 0.0 and 10.0 indicating the Jam Factor, which represents the expected quality of travel. When there is a road closure, the Jam Factor is 10. |
However, a reversible not routable status uses a Jam Factor of -1 as most applications do not want to display a blackout as a closure on the map. As the number approaches 10.0, the quality of travel degrades. -1.0 indicates that a Jam Factor could not be calculated.
|LE||Length of the stretch of road|
|LI||Unique string identifier for roadway|
|PBT||The base timestamp used for predictive calculations. The timestamp format follows the ISO-8601 specification. Example: 2011-07-04T22:02:46Z|
|PC||Point TMC location code|
|RWS||Collection of roadways|
|SS||Subsegment. SS is only provided if there is a current traffic data of subsegments (SSS) is different than the current traffic data of the flow item. |
The subsegment (SS) will be provided if the current traffic data is more precise than the flow boundary. When there are SS elements, the elements will be ordered by driving direction. If there are SS elements, the lengths (LE) of all SS elements will add up to the length of the roadway represented from the corresponding CF section.
|SSS||Collection of subsegments|
|SU||Average Speed Uncut for the road segment. Uncut means that the speed limit for the road segment is ignored. Speeds that are over the speed limit are included in the average|
|SP||Average Speed for the road segment. The average does not take speeds that are over the speed limit into account. Speeds that are over the speed limit are trimmed down to the speed limit|
|TMC||Traffic Message Channel location reference information|
|TS|| The Traversable Status (TS) can be set to |
When TS is set to
|TY (RWS)||In the RWS element, TY is a type of flows in roadway |
|TY (CF, SS, LN)||In the CF, SS and LN elements, TY is used when differentiating between various kinds of location types. |
|QD||This data type indicates the Queuing direction (QD) of the traffic. When traffic becomes congested, a queue of vehicles begins to build up in the opposite direction to the driving direction. The value can be "+" or "-". The value "-" indicates that the traffic is queued in the opposite direction to the driving direction.|