John Rowland wrote:
The other night I was standing in a road which had trees on both
sides every twenty metres or so, and also had lampposts at a
similar sort of spacing. It occurred to me that they could have
hung the lamps from the trees, and so not needed the poles, and the
street would have looked a lot better. Is there a reason this isn't
done?

In case you hadn't noticed, trees have leaves in summer, and sway in the
wind, so hanging a lamp from one is not a good way to light the road.
Mind you, Ealing erected some new lampposts close to trees a few months
ago. Perhaps the plans on which they based the spacing didn't include
the trees. One example is at
http://rjweb.myby.co.uk/images/Chisw...e_lamppost.jpg (The
post has since been moved.)

--
Richard J.
(to e-mail me, swap uk and yon in address)