Maybe radar for judging traffic load; or maybe it’s part of a toll pass system
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.
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.
