Where I live (Columbus, OH), mercury vapor is NOT common and most of the fixtures in my area are HPS and LED. Cobra heads, post tops, and high mast are HPS and LED. All MV fixtures are usually NEMA heads. Only time I’ve seen MV cobras were on private property. That’s it.

Grove City seems to use MH for their cobra heads on Stringtown, road which is interesting. As for post tops, most are HPS but some are MH, and spot replacements now are LED.

Do you live in an area where MV is common? If so, what is the most common post top, NEMA head, flood light, or cobra to find in MV (for older and modern models)? Interestingly enough, in Columbus, there are some LPS street lights.

I went on Streetview and MV seemed quite common in the Toledo area before they went LED (found MV OVZ’s, OVX’s, M400’s, M250’s, and even some MV UTR Traditionaires, P17M’s, or Mansard TC-100’s). Toledo, OH and associated suburbs had like a mix of HPS and MV in the city. They also seemed somewhat common in Cleveland and Cincinnati (Cincinnati also had a lot of MH street lights).

MV streetlights on the actual public roadways were fairly common here even in the mid to late 2010s, especially in older neighborhoods. But this decade, most all of the remaining ones were targeted for replacement with LED. Most of the MV lights that do remain in use are at private parking lots or private homes, where the owners haven’t bothered to replace them. Quite a few people still have functional MV lights in their yards or on their outbuildings.

Out where I am, I can think of one MV NEMA in a yard that’s still on the system and still functioning. Since it’s a private area light, it could still go for many years, because unless something happened to it, the power company won’t likely upgrade it unless the customer on the account calls them if it stops working or gets damaged somehow.

I can think of several abandoned MV lights that are still up on poles and out of service though, and the power company just leaves them up unless the customer wants to reactivate and they would then swap them to LED.

HPS is still pretty common here but I don’t think they’ve relamped any since maybe 2020 or 2021, so naturally they will begin to cycle and get replaced. I’m not sure how long an HPS lamp can last in regular service though. MV never cycles so that’s probably how so many of those lasted decades and were still in use. I’m really not sure when they stoped relamping MV here, but I suspect it’s been a few decades. It was recently discovered that one of the MV fixtures that was removed still had a lamp in it from 1985. It had stopped working for some reason a few years back, but when it did work it was actually still quite bright.

Down here in the Fort Lauderdale area MV was pretty much phased out in the mid 80s with the exception of a few older parking lots that were never upgraded.
HPS took over for roadway lighting and occasionally parking lots.
MH was once the most common for parking lots.
A few years ago pretty much all HID lighting was swapped out for LED, though there's still some HPS left on the Turnpike and I-95.

Not at all common here, I can count on one hand the number of MV lights in/near my town. Tons and tons of HPS though, so good enough for me.