Traditional? Street lights can be traditional? Wouldn't a traditional street light be a gas one?
It's probably my age that makes me baulk at this usage. Because I can remember those sodium lamps appearing. I can even remember the very first time I encountered them. It was in Sunderland, probably about 1968 or 1969. They were introduced even later than that in Newark. Not much more than 40 years ago.
Here's a phiosophical question. How long does a practice or an object have to have been around before it becomes traditional?