Induction. Is allready used for road lighting with good results

Ordinary Fluorescent. Most motion sensor systems only do dimming and not full off, so there is no problem of frequent starting

And induction can have a very long life, too.

They make T8's capable of 80K hours nowadays

I always thought that linear fluorescent streetlights were strange.

So when they switched from carbon arc lamps to incandescent, was the lighting collector community furious and demanding they not got with "fads" like incandescent lamps?
When they switched from incandaescent to mercury vapor, was the lighting collector community furious and demanding they not go with "fads" like mercury vapor lamps.

Lighting technology changes and improves. The towers are still there.

The lighting collector.. has no say in the matter.  They are the very low man on the totem pole.  Meaning, they can cry and complain all they want, it won't do one ounce of good. 

The lighting collector.. has no say in the matter.  They are the very low man on the totem pole.  Meaning, they can cry and complain all they want, it won't do one ounce of good. 

Unless you can take legal action.

Unless you can take legal action.

Legal action...no lawyer would even go near that as there is no legal action to be taken.  
wattMaster, you need to get your facts straight before you comment on something you really don't know anything about. I know you are trying to learn, but NOBODY would touch that, as there is no legal case, no laws were broken, they simply removed one light source for another, as they were told to!
It's not illegal for people to do the job they were told to do!

I thought it was about the lamp collector crying and complaining about the lamp bans.
But it doesn't seem like that has been talked about, as it likely doesn't apply much here.
Maybe the LEDs they are going to use will be better models than the ones we usually see?

Think of it this way. There are only 17 ford model T's left in the world (not sure if this is exactly the case, but just to show my point) and they all have original parts. But then someone comes along, says they are "inefficient" and converts them all to solar power, and their originality is destroyed. I get that the lights weren't originally mercury vapor and were converted to mercs in many years ago, but it has proven how reliable the technology is and how it was built to last that long. It wouldn't surprise me if they all have original ballasts in them too. LED is made to last for 5-10 years at most, then the whole fixture has to be replaced. I hope they are just using LED retrofits and not replacing the entire thing, but I don't see how any LED retrofit is going to be as powerful as a 1kw merc. Most LED retrofits I have seen are equal to a 250w merc at most.

If the LED device is custom made, it can be made to satisfy any wanted life time, reliability and brighness values. Not high tech challenge, just brutal size and big margins (so not loading to the edge) of all components