(moved from another thread)
quote:
Originally posted by sgrizzle
You want change made to downtown lighting? You need to talk to Crowley. Most of the big foundations listen to him and he is very pro-green development. The same foundations doing the development on riverparks with the much-improved lighting.
Since the Riverparks makeover lighting ignored so many rules of good lighting design, I have to disagree that simply changing a fixture style alone actually constitutes "improved". If anything, the implementation of the jogging trail lighting was done in such a way as to possibly dissuade their use by future designers.
Aside from cutting glare, Cutoff and Full-cutoff lighting fixtures focus their output downward at angles more useful to human vision. By not wasting light skyward,
less light needs to be generated by the fixture to do the job. That means you must reduce the wattage, or excess light pools under each fixture.
If you allow light to pool under fixtures, you not only waste electricity but your eye has a harder time trying to adapt between lit and unlit areas. That decreases your safety by making you less able to detect threats.
So why did we over-lamp the Riverparks fixtures in the first place?
Each municipal light fixture (streetlight, etc) maintained by the city must burn a minimum of 100 watts of electricity, according to Public Works.
It's not a rule that has an actual relationship to how well the streets are lit, but rather how much electricity the city agrees to buy from PSO.
As far as how to properly light streets to benefit human vision, improve safety and promote nighttime utilization of public spaces, it's an outdated rule and needs to go.
For the jogging trail, that means they could have used half the electricity and ended up with much better lighting. Given the human eye's higher sensitivity to blue-white light (Scotopic vision) we could have even used a third of the light used now, and improved visibility.
At those levels, we could have even used LED's or Compact Fluorescent, had better light, and saved money.
But we have to burn 100-watts per fixture instead...
And the rates just go up every couple of months.
The barriers to better streetlights are not technical, but political.Not letting our policy makers know we understand that is why we continue to loose city services like trash pickup and summertime pools everytime a new "Acorn" light adorns a downtown sidewalk.