[tgot]

I want this tied to a crude speed estimation algorithm, from a stationary camera.

Even with ALPR retention restrictions, I could trigger a video save and send the police a video of the idiots doing 50mph through the residential neighborhood.

[ALittleLight]

For speed estimation, I wonder if the simplest thing would be two plate readers a fixed distance apart. Say they're attached to light poles N meters distant.

When the reader triggers and takes a picture, it pings your server for a timestamp. It does the processing and records car X at time T provided by the timestamp. You then calculate the speed by the distance between the two meters divided by the time between the two timestamps for X.

Provided that speeding cars are a problem in your neighborhood, I bet you could find the people responsible for the light poles (which likely have power associated to them) to let you install the devices, especially if you're providing the devices and servers.

I don't think you'd necessarily be able to ticket the drivers though, as you're not law enforcement. Maybe you'd be able to work with local law enforcement though.

[tgot]

I was thinking of using the bounding boxes across frames.

Maybe I could work with a neighbor, but then things need to be tightly time-synced.

Zero chance I could get light pole access. A city endorsed surveillance system? No way.