This is very interesting. I had the same need a few weeks ago, which resulted in a tiny Golang/OpenCV project (https://github.com/kmmndr/motion-speed). In my use case, we even had champions beating 60 km/h, three times allowed speed
It's always interesting when you find out others are doing some obscure idea. Last year I was scraping supermarket data from a small country and I ended up setting up a discord with a half dozen of us sharing tips.
