On Jan 10, 5:17�pm, larry wrote:
wrote:
When you fly in and see all those parking lots lit up

The light illumniating the lot is doing its job

Waste light leaks and goes directly to the sky illuminating nothing.

Just thought I would point this out

why not use the same type camera system that changes traffic
� signals when there are cars around. �let the cameras turn
on the street lights where there is activity, and off after
an hour of no activity. �they have a long view from pole top.

most of our local lots now use 70 watt sodium bulbs, each
easily replaced at least ten 100 watt incandescent bulbs.
� lots that were on timers until 2am switching 6000 watts
now use photocells to switch 420 watts dusk to dawn.

dallas made a substantial power cut just by replacing all
the traffic signal bulbs with snap in led panels. �and cut
maintenance staff who's only job was continually replacing
burned out signal bulbs. �some intersection controllers and
signals are now solar powered. �all of the school zones are
solar powered, including the radio links that eliminated the
� � � �timing sync when they lost power. (no more school
zone flashing at 2am)

-- larry / dallas

the high efficeny sodium and other lamps take a few minutes to come to
full briteness.

by the time the sensor tripped light on vehicle would of passed.

plus theres liability issues if lamps fail for some reason....