Looks to me like a wireless traffic counter mounted on a streetlamp. Around here the city is building a wi-fi grid for emergency units that also use
short antenna on a pole every couple of blocks. I'd scan it with a frequency counter and find the band. Likely 5.8gHz. It would be nice to have
access to some of that.
It seems they are more than likely what was already mentioned above. Though, I've seen/heard things as such in Canada. Also, one time locally a
friend had a theory on a few strange looking objects that were mounted around city streets. One which made a noise, we figured that it was some kind
of mind control frequency.