What is calibration?
We receive many questions and doubts about the data collected by the Telraam, and the proportion between large vehicles and cars, during the first days/first weeks of counting by the Telraam.
At the end of the registration process, you will receive the following message:
Attention: Telraam needs time to calibrate.
This means that the data of the first hours and days are not reliable. This will improve by itself, as you use Telraam, and will take at least one week. The shorter the days (i.e. in winter), the less data the Telraam records. The calibration period then takes longer (up to three weeks).
Why one week? During the first week of counting, your personal Telraam has access to too little data, which does not allow it to establish a sufficient difference between cars and large vehicles (this is called the "cut-off"). This is why, in the first days, the Telraam uses a general rule to establish the cut-off. This is usually not correct, because this rule is general and not adapted to your specific Telraam.
Please note that in some cases, even after a calibration period, the distinction between large vehicles and cars is not correct. The number of cars is then underestimated and the number of large vehicles overestimated, or vice versa. The sum of the number of cars and trucks is usually correct. The car/large vehicle split point* is now roughly around pickup trucks. However, it is possible that large cars (SUV's, pickups,...) are counted as large vehicles and small, low-slung vans are counted as cars. To learn more about Telraam's vehicle classification, read this article, "How are the different types of vehicles classified and differentiated?"
Still, we ask you to be careful with Telraam's use of large vehicle count data. These data don't have the same accuracy as the Telraam data of cars.