I understand there are a lot of documents and papers on this in the Netherlands, since they have been measuring and experimenting for over half a century now.

I understand there are a lot of documents and papers on this in the Netherlands, since they have been measuring and experimenting for over half a century now. They don't just count vehicles, but also persons. If you're in government, maybe also see if you can contact the dutch Ministry of Infrastructure and Water Management (Rijkswaterstaat). https://www.rijkswaterstaat.nl/en https://www.rijkswaterstaat.nl/en