Inaccuracies In Telraam Data: A Quick Explanation

Do some statistics for your street segment seem strange to you? You might be right. Here, we explain why and when you might occasionally encounter inaccuracies in your statistics.

Telraam is constantly under development. It is possible that some data is not completely correct. Obviously, we are working on automated solutions to filter out bad data, but we’re not quite there yet.

On certain days or at certain times, Telraam’s classification of vehicle types (pedestrian/cyclist/car/large vehicle) may not reflect reality. There are several possible causes, and they vary depending on the Telraam. For example, this classification issue can be caused by the position of the sun, which can make the shadows of cars or bikes appear larger than they really are.

Besides local issues specific to your Telraam, some inaccuracies can be more easily explained.

According to Telraam, my street is heavily used by large vehicles. This does not ring true to me.

You’re probably right. Sometimes, Telraam has difficulties distinguishing between cars and large vehicles. It is possible that large cars (SUVs, pickups,…) are counted as large vehicles and small, low-profile vans are identified as cars.

Telraams that have been active for only a short time use a generic and therefore less accurate method to establish the difference between a car and a large vehicle. Some Telraams will therefore count far too many, or far too few, trucks. This will improve when several weeks of data are available and the monthly update is implemented. As more data becomes available, the distinction between cars and large vehicles will continue to improve. So keep counting!

Want to learn more about how Telraam classifies road users? Click here.

Cyclists, pedestrians, cargo bikes, groups of cyclists,… How does Telraam count them correctly?

The difference between cyclists and pedestrians is not always obvious either, especially if several pedestrians or cyclists are riding together. In such cases, Telraam classifies the vehicle type (cyclist/pedestrian/car/large vehicle) based on size and speed.

  • Cyclists pushing their bikes or pedestrians with strollers are then counted as cyclists.
  • Joggers, even if they are related to Usain Bolt, will be identified as pedestrians.
  • Groups of cyclists form a single large object and represent a specific situation that Telraam can hardly distinguish: they will then be counted as a car.
  • Similarly, some cargo bikes or bike and trailer combinations will be counted as cars too.

What happens if there is a traffic jam?

If there is a (long) traffic jam without movement for several minutes, Telraam will not work properly. It will indicate so, by labelling the data collected during the traffic jam as “poor quality”.

What can I do to limit or solve inaccuracies?

  1. If your Telraam is new, give it some time to calibrate. This may take a few days. Click here to discover why Telraam needs time to calibrate.
  2. Check your camera to make sure it’s installed properly and the images it gathers are of sufficient quality. Click here to learn how you can check your camera.

The issue persists? Inaccuracies remain and cannot be explained by the information provided here? Please send an e-mail to and briefly explain your situation.

You can get more detailed scientific info by reading our report on potential inaccuracies in Telraam: Potential inaccuracies in Telraam.pdf (1.4 MB).