The upright looks like it has a couple line of site antennas and a power/network box probably. Looks like it is running/networking the device pointed downwards. That device likely has a series of sensors for detecting vehicle traffic. This setup helps track traffic for traffic control.
Those circles are probably too small for normal ISM comms links, they are either radar cans or microphones is my guess. The fact that they both have two feeds makes me assume radar.
Context would help. General location (state, country, etc)? What kind of road? Were you near any other car infrastructure? Are the directionals pointing at anything informative?
I suspect the box facing down is some kind of short range antenna. Like for reading toll passes kind of thing, though I doubt this is that. The directionals first reminded me of like IR sensors for like emergency vehicle signalling, but you'd normally see that on a traffic light.
Oooh this setup just got installed on a highway in my town, I've been wondering what it was since it was installed just past one of the vehicle counting strips they use
it was on a street light after an intersection, in California. from the comments it would make sense to be for traffic control. My original thought was a gunshot detector since I remember hearing they installed them in the city but doesnt seem that this is it
The rest of it is point-to-point wireless networking antennas. Not sure which technology but it's probably something specific to emergency alert/law enforcement.
The rectangular box in the back is a standard NEMA box that houses the electronics/power supplies for the other components.