These cool looking roadway lighting systems used continous HO/PG fluorescent lights embedded into special railing luminaires and were typically used on bridges and elevated highways. They were for the most part installed during the 1960s and have since been removed and replaced with more conventional forms of roadway lighting due to problems with maintenance and reduced light output in places that snowed during the winter.

When the elevated portion of the Gardiner Expressway opened, Toronto had such a system on the ramps and merges of the Gardiner Expressway. They were disconnected and mostly removed when the lighting was switched to LPS in the late 1970s. Here is a archival photo showing the system in use in the 1970s. The ramps and merges and the median barrier were lit up.

Hololulu, Hawaii also had such a system on some of their freeways. This system appears to have been removed sometime between 2011 and 2019.

The last such installation that remained intact and functional until recently was the Dorland J. Henderson Memorial Bridge. The original span had a fluorescent railing lighting system. The bridge was twinned in the mid 2010s and the original span reconstructed. Unfortunately the new roadway lighting system consists of pole mounted LED luminaires. However in a nod to the original railing lighting system, the exterior of the railings are lighted on the reconstructed span.   

There's a few other installations listed in that thread but so far none appear to still be functional, much less still in place.

So anyone know of any of these cool 1960s and 1970s relics still in use, or even still in place?

Who knows, maybe with the advent of LED, systems like these might become installed again.