We get a lot of questions and doubts about the data and relationships between large vehicles and cars, the first week/days that a Telraam counts.
At the end of the registration procedure you will receive the following notification:
CAUTION: Telraam needs time to calibrate itself.
This means that the data of the first hours and days are not reliable. This improves automatically the longer your Telraam is active. This takes 1-3 weeks.
Why a week? During the first week of counting, there are too few data points to make a good difference between car and large vehicles for a specific Telraam ("cut-off"). That is why the Telraam uses a general rule for this cut-off during the first few days. This is of course much less correct, because it is not specific for the Telraam.
Note that in some cases, even after a calibration period, the distinction between large vehicles and cars may still not be accurate. The number of cars is then underestimated and the number of large vehicles overestimated, or vice versa. The sum of number of cars & trucks is usually correct. The dividing point car vs large vehicle* is now roughly around vans. However, it is possible that large cars (SUV, pickup,...) are counted as large vehicles and small, low vans are counted as cars.
This entire system is continuously evaluated and, if possible, a new cut-off is made specifically for each Telraam.
However, we always ask you to be careful when using counting data from Telraam of large vehicles. These data do not have the same accuracy as the Telraam data of cars.
* Large vehicle includes: Vans, cars with trailers, pickups, light and heavy trucks, buses