I'm probably just stabbing in the dark with this one. Back in the early 80's back when I lived ion Connecticut , I remember seeing MV tunnel lights unlike anything I remember . I got a decent look at one while we were sitting in stopped traffic in the tunnel . The fixtures were 400w MV with clear BT-37 lamps in various states of disrepair . What caught my attention was the fact that these lights didn't have a conventional socket . The lamps were mounted horizontally with spring clips retaining both the BT end and the base with another spring to contact the center contact of the base . Non of these had any form of refractor left that I remember and quite a few either didn't work or had missing lamps .

 Has anyone ever seen or heard of such a thing or is my memory just playing games with me .

 I believe the tunnel I remember is what's now called the "heroes tunnel" on the Wilbur Cross Parkway The current lighting appears to still be 180w SOX as of January of 2022 !  https://goo.gl/maps/SKihc52JLu77trHP8