Since the new columns have been installed my garden/path/drive is no longer lit by the street lighting, why not?
Only the adopted highway should be lit by the street lighting system, although older equipment did tend to spill light over much of the surrounding gardens, etc. The new installations concentrate the light where it is needed, on the road and pavements, while reducing or eliminating spill light and upward light pollution. This is much more efficient and is kinder to the environment, but does mean private areas won’t now be lit.