Even though the Highways Agency was created in 1994, local highways authorities continued to have fingers in the pie and an influence until the early 2000s. I think there was a bit of a transitional period where the Highways Agency in effect became the client and the local highway authorities were essentially consultants/contractors for them. Following on from this, the trunk road network was reorganised into a smaller number of larger areas which typically span multiple counties. Hence, trunk road lighting from the 1990s has a much more "local" feel. Of course, there is also the sort of thing that happened with the creation of unitary authorities, where it typically took a few years for "preferences" of the separated councils to move apart.

It was the Hampshire County Council influence that meant the M27 got Urbis ZX4s. It was also the Hampshire County Council influence that saw a mass lantern replacement of MA50s and MA60s with ZX3s, something which spanned motorways, trunk roads and the Hampshire road network.

It looks as if your theory is right, Sotonsteve, as I carried on along the road on Streetview to see if I could see any clues of any Redbridge ownership and right at the end of the road, as it comes to a dead end, there's a Redbridge sign! Here the LED lighting ends and white ZX3s (Redbridge's staple lantern from about 1995 up to about 2005) appear before the SGS204s take over. The SGS204s therefore seem to be an unusual choice for Redbridge. They were used en masse on a couple of roads in Redbridge and probably would have been installed in the early 1990s, but these particular examples were installed when the bypass opened in 1999, when the ZX3 was the preferred lantern, and the SGS204 was used as a casual replacement lantern only.

I was in Ilford Town Centre yesterday and managed to indirectly get a shot (see attachment) of the new TRT Aspect lanterns which retrofitted 1980s spheres on the candelabra brackets about 2 months ago (I was pre-occupied with a live music event and completely forgot about wanting to get pics of the lanterns). I think they just look totally hideous and completely spoil the effect of the brackets! Thankfully just down the road some 1980s spheres (which were missed last year in a Pilzeo retrofitting scheme) still survive, so there are still some decent-looking installations in the town centre.

Look better than the globes in my eyes.

So who would have been in charge of the lighting prior to the HA in 1994? There used to be plenty of evidence of the typical trunk road lighting seen in London e.g. MA60s on Octagonal steel columns, which has gradually been phased out since TfL. I remember when TfL was first formed their lantern of choice - certainly in West London at least - was the Riviera, which cropped up on various stretches of the A40 and A406. TfL have since then been rather keen on using TrafficVisions and Iridiums.

As you say there seems to be plenty of evidence for local authorities influencing the choice. I know parts of the North Circular that fall within Enfield use Arcs - not sure if this is a coincidence or not.

In the case of the examples I mention in my last post, here are the GSVs:

SRL 8s on Barnet columns installed on a side road adjacent to North Circular Finchley Bypass (opened 1996)

MRL 6s installed on road bridge over Finchley Bypass on Barnet columns

This side road used to be headed with P567s (as used on the slip-roads for this section of the N. Circular) but SGS203s have since been retrofitted

Before 1994 the local highway authorities looked after motorways and trunk roads on behalf of central government (Ministry of Transport and all the various different names it has had), receiving central government funding for construction and maintenance. Hence, with the creation of the Highways Agency there was that transitional period where local highway authorities still had an influence, before influence was progressively stripped away.

So who would have been the local highway authority for, say, the M25 - most of which was MA60s on octagonal steel columns all the way round? It seems too much of a coincidence that trunk roads within Greater London also adopted such installations as you'd have thought the local highway authority within which it fell under would have used bog standard stock.

The M25 is predominantly in Kent, Surrey, Buckinghamshire, Hertfordshire and Essex. I'm not entirely sure, but where there were small boundary overlaps such as Greater London and Berkshire I think the agreement was for a neighbouring authority to look after it for consistency purposes. Essentially, you had Road Development Units, which were a branch of the Ministry of Transport in central government, and then you had sub-units which developed and looked after the network. For example, there was a south east road development unit, and a Surrey sub-unit within this.

There were far from MA60s all the way round the M25. Essex and Hertfordshire heavily lit their sections of M25 with MA60s from the outset, but Kent, Surrey and Buckinghamshire sections were largely unlit when built, only becoming lit when widened.

In terms of lighting stock, motorways have always been something of a special case, as the lighting standards for motorways are different to what is permitted on local roads. Lanterns installed on motorways had stricter cut-off of lighting distribution and were almost always integral gear, plus being motorways rather than local roads, columns were typically taller. Nowadays 12m columns are commonplace, but back in the good old days a 12m column was reserved for only the best location!

Saw this afternoon that these Urbis Sepales on the A1306 through Rainham and Dagenham are in the process of being retrofitted with these butt-ugly Induction Indo ST90 lanterns. This continues the discussion above as to whether the responsibility for de-trunked A roads in London lies with TfL or local authorities. I reckon that the A1306 (what was the A13 until the late 1990s) is run by the local councils as Induction Indo ST90 lanterns were used a couple of years ago on the stretch from Rainham to Wennington as retrofits for SGS203s. The Sepales were used on a stretch through two boroughs: Barking and Dagenham and Havering, which would have been before TfL formed in 2000 (the new A13 was opened in 1998, so I reckon this was when the road was de-trunked to the A1306), so I reckon the Highways Agency installed the Sepales but the responsibility for them now lies with local councils.

Looking at the GSV it seems one column had already been retrofitted with an Arc. It seems, even the 'designer' installations aren't safe from developments.

I've mentioned this before (but can't find the original post), but a pub car park in Winchester has what I presume is SOX floodlight (rather than SLI) lighting its car park. It still was working, however recent refurbishment at the pub, has seen the floodlight removed and replaced with what looks like a MH floodlight.