Regarding municipal street lighting fixtures being "serviceable": NOPE. I work at a DOT. If it's not a photocell, the entire fixture is replaced. The LED driver/power supply seems servicable in most fixtures, but no one bothers. Whereas a HID fixture was either a BO Lamp or inop photocell, no one bothers servicing a LED fixture. My opinion? Flashing/strobing/dark street lights are most likely a failing/failed LED driver. If it were up to me, I'd at least try swapping the driver first, but my co-workers don't understand electricity....even though it's their job to work with it!

Thats interesting as thats not the practice where I am, UK street lighting crews here do replace drivers, and if they have to take a fixture down for a new one, the old one isn`t binned, rather it goes back to the depot to be re-fitted with whatever it needs.
I also do this with our LED yard lights at work, (yes I have new ones), but when one fails its swapped for the new one, but the old lantern doesn`t go into scrap.

Its easier to take it back to the workshop, strip it all down and then re-place the driver, (usually dead due to water ingress), and fix where the leak is, generally clean it up, then put it back on the spares shelf, (for use the next time one goes EOL).