As Oak Park strives for operational efficiencies within a framework of environmental sustainability, streetlights are getting some special attention.
The Public Works Department is testing new LED lamps on four blocks in the community to find the best replacements for the inefficient mercury vapor bulbs that had been the light of choice for municipal streetlight systems for decades.
The test is underway on the 100, 200 and 300 blocks of South Taylor Avenue and the 100 block of South Humphrey Avenue. Residents are invited to visit the test blocks and share their views at www.oak-park.us/streetlightsurvey.
Oak Park has about 6,000 lights on streets and in alleys. Most have 100-watt mercury vapor lamps, which lose more than half of their output within just a few years.
The LED lamps being tested also emit the equivalent of 100 watts, but they maintain about 90 percent of their output for the life of the lamp, which also is much longer than that of a mercury vapor lamp.
The Village is doing more than just testing how well the new longer-lasting, more energy-efficient lamps work with existing equipment. The lamps on each test block also have different color ratings, which affect how well the human eye detects details.
The light colors, measured as ratings on the Kelvin scale, range from 2500K, which is similar to orange commonly seen with Chicago’s sodium vapor lighting, to 4000K, which is closer to the bright white incandescent bulbs sometimes marketed as daylight.
Oak Park’s public works engineers say they prefer the 4000K lamps because the higher on the lighting scale, the better the human eye can pick up details — an important factor from a public safety perspective.
With most of the lighting to be focused downward, the harshness sometimes associated with lamps rated higher on Kelvin scale will be diminished and light pollution minimized, officials say.
Plans are to focus first on the 2,500 street lights in residential areas. The retrofits likely would be phased in over several years. The last time major improvements were made to Oak Park’s streetlight system was in the 1970s.
For more information on streetlights in Oak Park, call 708.358.5700 or email firstname.lastname@example.org.