In article ,
clumsy ******* writes:
David Hansen wrote:

Because electricity was too cheap and so councils generally didn't
bother, especially when they switched from time clocks to
photocells. However, there were places in the 1970s where the street
lights went off at around ISTR midnight, I suspect that at the time
they had not been converted to photocell operation.

There was a large new estate near me where all the original small
mercury vapour lamps went off at midnight. There was an enormous
campaign to have them on all night, and the council eventually
replaced them all with low pressure sodium on photocells (which
was cheaper to run than the mercury ones switching off at midnight).

they are also supposed to deter crime and reduce accidents, its
something that changes as priorities change, no doubt "green" is now a
bigger consideration, but lampposts are usually not brand new.

They turn out to have a much more significant crime reduction
effect than CCTV does, something which the government reminded
local councils a number of times as they were all fighting for
large funds to install and run CCTV systems.

None of the currently used streetlamp technologies are much
good for frequent switching. Indeed, the technologies have been
driven mainly by minimising relamping costs, and the technologies
used currently really depend on only one switchon/day for the long
lamp life. Allowing people to switch them on for 15 - 60 minutes
as was done in the German trial would add enormous costs for
relamping, using current the current technologies.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]