Re: Let there be light!
"My large town switches off all the street lights at midnight - leaving only a few high level clusters on major roads."
LED plus sensors means that they can be dialled back 90%, but still fire up as cars/people go under them (the lamps communicate to adjacent poles, so it's not just the one you're under which lights up). This technology has been around a few years now.
As for energy costs, the single most expensive part of any streetlamp's operation is getting a bloke to change the lamp. Traditional ones are rated in on/off cycles as well as hours, so switching 'em off early may not make them last any longer and does bugger-all to save money overall. That sounds more like someone with a fetish for dark skies (Any amateur astonomers on the council?)
The pitch black conditions and increased nighttime accident rate sounds like a perfect oppportunity for compensation lawyers to wipe out any savings made - and then some.