Work around frequent errors in TMC data
Many TMC services send out erroneous or incomplete data, and experience shows they often do not realize it until made aware of it. Recent examples include:
- Weather reports with durations of 24+ hours
- Accident (with an extent greater than 1) but no traffic problem reported, though in reality there is stationary traffic
- Closure reported at a motorway interchange (extent=0), with no indication that it refers to the connecting carriageway
Imprecisions in event/supplementary information data (including supplementary information which carries location information) are often the result of the broadcaster’s toolchain, which often caters to a bunch of others services (web, TPEG…), may not be optimized for TMC and introduce various errors.
Guess what is really meant:
- Duration of weather reports capped to a few hours
- When an accident is reported, extent exceeds 1 but no information of traffic information, add “traffic problem expected” in the TraFF feed
- When a closure is reported with extent=0 and the location is a motorway junction, assume it refers to the connecting carriageway, not to the main road.
Benefits of the solution
- Reports reflect the actual situation more accurately
- TraFF consumers need to do less magic on their end (which may only be needed for TMC, not for other sources)
- This list is never going to be complete.
- Results will always be guesses, never as accurate as a correct report, but may compete with more accurate messages if the consumer has access to other sources as well.
- There is a risk of mis-guessing information, fixing what doesn’t need to be fixed, and thus introducing errors.