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.

My town did have lots of mercury and HPS NEMA Heads before switching to LED in 2016. The two other major utilities in my area haven't had MV in 25+ years.

Since i was alive/aware in the 1990s, i've never seen them as public street lighting. It always was HPS, linear fluorescent or PL.
Private street lighting like factory terrain or parking lots absolutely had a lot of them.

Around Spain it is quite rare to encounter mercury vapour fixtures WITH MV bulbs, but not without them.

Small villages around my country have had this technique to save costs with lighting, replacing the old bulbs with cheap Indoor LED bulbs, or just more exterior-based LED bulbs, mostly corncobs unfortunately.

But the encounter of Mercury Vapour itself is not so rare, specially when visiting old Mediterranean neighbourhoods from the 1960s-1980s where the boom in tourism happened in Spain, most councils in charge had poor or low budget regarding the maintenance, so little to no care was put, an example i'd give would be Santiago de la Ribera, their street lights date back to the 1980's, some are still in place with Mercury Vapour, some have been switched to LEDs, and some have been done a poor replacement with a fixture from another local city or village, which makes it kind of out of place for the street.

Around early this year (starting March 2026) they've been starting to replace sections with new LED fixtures and masts, glad i've archived photos of them beforehand (January 2026).

In the Northwest of Spain, there are many fixtures dating back to the 1970s still standing in smaller villages, since the north of spain is more separated between very tiny villages (with at least 2 or 3 houses!), they still have the same LED treatment but some are still under MV, either due to no need for modernization or missed during maintenance.

Mercury vapor streetlights haven't been common where I live for decades.  There used to be many areas of town that had MV streetlights.  Most were old clamshells, but there were many cobraheads too.  I only know of one street that had NEMAs.  In the summer of 1994, they were all replaced with HPS cobraheads.  There was one neighborhood where the streetlights were owned and operated by the RSA, and it had mostly MV cobraheads with one or two streets lit with cube-shaped MV posttops.  By the fall of 2006, the cobraheads all went HPS and the MV cubes were replaced with HPS shoeboxes.

During the short time that I lived in Louisiana, that town was mostly lit with MV NEMAs.  By 2008, HPS NEMAs were being installed for new installs or spot replacements.  When I visited the town 10 years later, LEDs were starting to appear, again as new installs or spot replacements.  The existing MV and HPS NEMAs were still being maintained.  Proof of that was that all of the bulbs that I could see in the MV NEMAs were BT28 in 2008 and ED28 in 2018, so they had been relamped in that time.