Wednesday, March 9, 2016

Correcting the Record about the Cost of Streetlights

We welcome neighborly debate about streetlights on Springdale. A neighborly debate must not be based on false information, however. Inaccurate information appears in a flyer just circulated in the neighborhood. The purpose of this post is provide corrections about the cost issue, in order to avoid confusion.

You can support streetlights without contributing a penny to the upfront costs. 

It is simply untrue that "the cost is likely to be at least several thousand dollars for each house that signs the petition." Instead, the average upfront cost is likely to be approximately $1200. Supporters who cannot contribute or do not wish to contribute will face no upfront costs at all.

Funds for the upfront cost will come from fundraising. The Druid Hills Civic Association provided financial support for Oakdale. The rest of their funds came from contributions from the neighborhood. We plan to fund the upfront costs the same way. While we encourage financial support for this effort, you can support streetlights without participating in the fundraising.

Your support is needed even if you don't wish to contribute to fundraising.

Our approach has been to canvass the neighborhood based on a good cost estimate derived from Oakdale's recent efforts, past quotes for Springdale, and information from Georgia Power. Meanwhile, we are working with DeKalb County and Georgia Power on a concrete plan. Fundraising for upfront costs will begin only after 51% of the neighborhood decides to support lights.

We hope to contribute to an open dialog based on the facts. If you have been confused by the previous flyer or would like more information, please reach out to Bill Aitkenhead at aitkenhead@gmail.com or 404-565-0075.

Thursday, March 3, 2016

Neighborhood crime data: fewer car break-ins with streetlights

Data from CrimeMapping shows that over the past six months there have been fewer car break-ins on Oakdale and on lighted sections of Springdale than on our dark section between North Decatur and The By Way. There were thirteen car break-ins on both streets combined. Seven of the thirteen were on our segment of Springdale. CrimeMapping data includes all crimes reported to DeKalb County police. The statistics below also include Atlanta police crime data.


Tuesday, March 1, 2016

Streetlights are not strong enough to upset your circadian rhythm

This post was researched and written by a member of the Streetlights Committee:
Recently, there has been a lot of attention given to the issue of light exposure and its impact on circadian rhythms. This is very appropriate given the proliferation of LED screens in mobile phones, computers and televisions. LED screens emit a type of blue light that, particularly in the evening hours, can significantly impact sleep patterns and lead to a difficulty sleeping. The current recommendation for good sleep hygiene is to limit use of phones and other devices with LED screens for 1-2 hours before bedtime. 

In contrast to LED screens, however, other lights used in homes do not significantly impact circadian rhythms. Melatonin is the hormone in our brains that regulates our circadian rhythms. Bright light, such as sunlight during the day, suppresses melatonin levels and signals daytime for our bodies. The influence of light on melatonin levels, however, only occurs with bright lights. Light influences circadian rhythms only at levels beyond 100 lux (100 lumens per square meter). Considering the typical family room lit up at night is 50-75 lux, one can imagine the intensity of light needed to impact circadian rhythms. Bright lights, such as the fluorescent lights used in office buildings, would affect melatonin levels and circadian rhythms; rooms inside homes are typically lit at a intensity less likely to. 

When we extend this discussion to street lights outdoors and the impact they can have, it is clear that they would not have an effect on individuals who are indoors many feet away. When standing on the sidewalk right next to the streetlights that would be installed on Springdale, the brightness is only 18 lux. The intensity of the lights dissipates as you move farther away. At 50 feet away, it is 3 lux. At 67 feet is it the brightness of a full moon, which is 0.3-1 lux. Inside a house, the brightness would be reduced both by distance and windows. All of these levels are far below the level that would be needed to have an effect on melatonin levels that impact circadian rhythms. 

In summary, although the impact of light on circadian rhythms is an important concern in our lives these days, much of the issue relates to our use of devices which use LED screens. The impact of other forms of light are nearly negligible unless specific rooms are lit at levels 1.5-2 times the intensity used in typical homes. Street lamps outside of a home would not affect melatonin levels given their very low intensity and how that intensity diminishes at distances many feet away from them. 

Sources on Circadian Rhythm:
  • Duffy JF and Czeisler. Effect of Light on Human Circadian Physiology. Sleep Medicine Clinics. 2009; 4: 165-177 
  • Zeitzer JM, Dijk DJ, Kronauer R, Brown E, Czeisler C. Sensitivity of the human circadian pacemaker to nocturnal light: melatonin phase resetting and suppression. Journal of Physiology. 2000; 526: 695-702
Source for Springdale streetlight specifications: 
  • King Luminaire Co. Certified Test Report No. LSC A003

Monday, February 29, 2016

How bright are the lights?

This light intensity map is derived from data about the lights that would be installed on our street.

The lights are designed so that 60% of light emitted is directed toward the street, and peak illumination is projected up and down the street rather than toward properties. At 75 feet away, on the street side, the lights are no brighter than the light of a full moon (technical term: .25 -1 lux). There is less brightness on the sidewalk side of the lights.





Source: King Luminaire Co. Certified Test Report No. LSC A003