7 years ago, Duquesne Light replaced thousands of mercury vapor street lights with high pressure sodium ones in several municipalities in Allegheny County. Now they plan to replace 1,500 street lights a year from HID to LED's. Shame on Duquesne Light and the municipalities who are going along with it. They're making a terrible mistake, it's not like there are any significant cost reductions to the customer because LED fixtures are still more expensive than high pressure sodium ones and the distribution and maintenance costs are higher so switching to LED's won't save municipalities any money. 

Read more:  http://powersource.post-gazette.com/business/2014/09/23/Duquesne-Light-turns-on-LED-streetlight-plan/stories/201409230016

Not to mention that the expected service life of the fixture is on par with the service life of a typical high pressure sodium lamp, and is far less than that of a quality high pressure mercury lamp.
The accumulated knowledge of 135 years of electric lighting down the drain.  Welcome to the new dark ages.

Currently the manufacturers, importers and VAT/sales tax collectors are laughing all the way to the bank. I have a suspicion that this is going to bite the authorities installing these things right on the a** ..


BG