Delivery Radar

Are you ever curious just how fast delivery riders and hacked e-scooters travel down cycle paths? GPS apps like Strava could tell you how fast you are going yourself, but not how fast somebody else is. In principle, you could automate that. First record some precise reference points on a cycle path of your choice. If planning an official complaint, you might think how to secure that data. Then you'll need some video with accurate timestamps to verify the velocity as the rider's front wheel passes each point. Finally, what is the most effective way to campaign for better regulation, as an alternative to motorist campaigns against cycle lanes?