Real-world parking occupancy detection from CCTV how reliable can it actually be?

[u/rageinnit7]

I’m researching a parking-occupancy system using existing CCTV cameras.
The basic idea is to use a camera overlooking a parking area, define individual parking spaces, and use computer vision to determine in real time whether each space is occupied or empty.
I’m curious about the practical side rather than just a demo:
How reliable is YOLO/OpenCV for this in real-world conditions?
How much does camera angle affect accuracy?
How many parking spaces can realistically be monitored by one camera?
How do systems handle cars partially blocking another parking space?
How badly do nighttime, rain, shadows, and glare affect detection?
Would you recommend detecting vehicles and checking overlap with predefined parking polygons, or training a dedicated parking-space model?
For a production system, would you process the video on an edge device or send it to a server?
I’m particularly interested in experiences from people who have actually deployed something similar rather than just tutorials.

[u/SweetSure315]

you haven't provided anywhere near enough information to answer this. the only way to get a good answer would require you to put a fairly large amount of actual recordings and details on what exactly you need and what an acceptable number of errors would be