@Rommie: Indeed, of course the installed HID and fluorescent fittings won't last forever but there has been so many replaced well before their time it is rather a waste.

@Beta 5 - Yeah, it's a trend I've noticed here too. Sometimes brand new lights, less than a year old get swapped out for LED. Now I suppose with HID, especially outdoor roadway HID, it's harder to get a beam pattern match for a retrofit but for fluorescent the retrofit offerings are pretty decent and allow luminaires to remain in service until they're actually worn out.

I'll never forgive the council here for sneaking in while we were on holiday for 2 weeks and replacing the entire street's contingent of HPS Arc80 lanterns, none of which were faulty, for the most awful crappy cheapo L*D monstrosities you've ever seen in your life   

our local utility decided in 2014 that EVERY light they own will be LED and then they removed and disposed of 1000's of working lamps with working bulbs in them just to fit LED "autobahn" lamps that in 2-3 years all NEEDED replacing due to BAD quality / premature failure and being NON "relampable" now we have a "broke" utility and landfills "full" of good lamps and the environmentally "harmful" bulbs plus a cities worth LED lanterns that are 2 years old 

Cheshire East’s street lighting department was rapid when changing our street lighting, and I mean rapid!
There was just 5 guys, 2 in the column truck, two in the bucket truck and one in a little service van!
They started one December Saturday morning, and I remember going Christmas shopping early that morning, we left our house under the glow of our 35 year old SOX street lighting, and returned 12 hours later to 80 % of our town LED up and running on new steel columns!

It was sad to loose our SOX, but at the same time, bloody impressive with how fast these 5 lighting engineers had worked the Saturday! 

2 weeks ago the street that my mail box is on only had ONE street lamp @ the intersection of the cross streets so ONE a block
was that way when I left Tuesday morning and returned that night to find 5 NEW lanterns AND poles installed wired in and running (Monday was a bank holiday so hydro was NOT open)

@ Rich - It was downright criminal to lose all that SOX; nothing to be impressed about at all, except for how stupid and short-sighted some people can be 

@Rommie Angry horse lost the SOX/LPS I had NOTHING and "gained" 5 fixtures on a street without lighting
SOX was never popular if at all used by Hydro in my area we had Merc's replaced with SON and then LED in 2015 leaving "decorative" and 1X SON fixtures as "LED dont go that high" during the changeout that cost Hydro FAR more then they "banked" on and the mass swap out is OVER for NOW
I would CRY to see SOX killed for no good reason beyond "moving forward"

Maybe not the SOX yes, our top entry Beta Fives were only 35 years old, but our concrete columns that they were on were circa 1950, so they were due probably for safety reasons?
What was impressive was the removal of well planted, 60+ year old columns, including disconnection, (probably lead covered cables), splicing in new cable and cutout, planting and concreting new steel columns, then filling in the holes and getting them up and lit in large quantities in just one day!

Putting aside the light source and equipment for a minute, to do that level of electrical work as fast as they did it was good going from an installation point of view?

it is an impressive feat of "engineering" to do all that
mine was purely installing arms onto the existing power poles and running the switched cables to the fixtures and maybe fitting a new group switch (have not looked yet)

An impressive feat of engineering it may have been, but that's not the point. It was an unnecessary impressive feat of engineering, which is what makes me angry 

It has surprised me how much fluorescent is still in use in some places even now approaching 2 years since the ban. That being said, sourcing new lamps has started to get a bit more difficult. A lot of online lamp stores and shops that previously stocked fluorescent no longer do.

This leads me to wonder - what will the effects of the HID ban which is just over 1.5 years away be? A lot of HID lamps (e.g. SON above 150W, dimming SON, CPO-TW, CDM of all types, etc) dont have genuine retrofit replacements or any at all. There is the possibility of an extension but I dont see it as likely. My guess is that such fixtures will have to be replaced outright for new LED ones (which is already happening at pace anyway), as I dont see new retrofits coming onto the market to prevent this. Retrofits for the smaller lamps like CDM would be very challenging when it comes to thermal management and optical control, and dimming capable ones would be difficult too (even though dimming fluorescent retrofits are now available).

We are stocking up with CPO 45W and SDW-T 50W lamps as these are the only HID lamps left in use in our city and will most likely remain past 2027 till about 2032.