Committee on Transportation and the Environment
Public Roundtable
Sierra Club DC Chapter testimony by Wayne Savage
March 26, 2021
Thank you for convening this meeting, Madam Chair.
My name is Wayne Savage, representing the Sierra Club DC Chapter.
With more than 3,000 D.C. dues-paying members, our chapter has an active interest in energy efficiency, along with environmental and public health.
The Sierra Club strongly supports the LED conversion project for its potential to reduce energy usage.
We believe, however, three elements of the proposed RFP must be revised to take full advantage of LEDs energy efficiency and to reduce their environmental impact. This committee should closely scrutinize the amount of light (commonly called "brightness"), the quality of light, and where it shines.
First, the amount of light is critical because energy usage is directly related to brightness.
Nighttime light also disrupts our circadian cycles, alters wildlife behavior, and causes urban skyglow that disorients some species.
Recent studies link outdoor light at night – especially the blue-wavelength emissions of LEDs – to harmful impacts on human health, including cancers, lymphoma, and anxiety disorders.
The science therefore suggests that outdoor nighttime light should be used sparingly – only what is truly necessary.
So what light levels has DDOT proposed? The agency's stated target for LED lighting is the District's current light levels. This is troubling because many DC streets are excessively lit – far beyond what is sufficient for traffic safety according to national standards. Local residential streets, for example, have seven times the minimum amount of light recommended by the American Association of State Highway and Transportation Officials (or "AASHTO" for short).
DDOT estimates that under its proposed RFP, most DC streets would still have more than twice AASHTO's recommended minimums, and some would have nearly three times as much.
DDOT states that LED fixtures could be dimmed at the request of neighborhood residents. This implies, however, that all the District's streets would be overlit initially. Instead, the default standard should be the minimum light levels recommended by national standards, and no more.
DC residents rely on street lighting for a feeling of personal safety, and some streets undoubtedly need more light. Adhering to the minimums of national standards would correct many instances of inadequate lighting. DDOT also could provide a process for residents of geographically limited areas to request upward departures from the minimums.
Second, what is the quality of the LED light? Compared to older lights, LEDs emit greater amounts of blue light, the most biologically active component of white light. Blue light also is a major factor in skyglow, and it produces more hazardous glare that impairs the vision of drivers.
The American Medical Association (the "AMA") recommends that street lights have a color temperature of 3000 Kelvin or lower. (The lower the Kelvin rating, the less blue light.) The AMA also calls for "the lowest emission of blue light possible" to reduce glare.
Installing warm-white, 2700-Kelvin LEDs helps reduce glare, improving driver vision and making it easier for pedestrians to assess the safety of their surroundings.
DDOT's RFP does call for 2700-Kelvin LEDs on residential streets, an enormous improvement over earlier plans. But 3000-Kelvin fixtures are slated for many busier streets with the brightest LEDs.
The experience of other cities suggests that DDOT can light all the District's streets to AASHTO standards with 2700-Kelvin LEDs. Phoenix, for example, has successfully installed 100,000 2700-Kelvin street lights, regardless of street category or surrounding land usage. DDOT should follow that example.
Finally, where will the LED lights shine? Under DDOT's proposed RFP, Washington Globe and teardrop fixtures would shine some of their light directly into the sky, wasting energy and adding to skyglow. The RFP should be revised to specify only "full-cutoff" fixtures that eliminate uplight and reduce glare.
Thank you for the opportunity to address the committee. The Sierra Club believes our suggested revisions to the RFP are consistent with the DC Sustainability Plan and will help make the District a national model for safe, healthy, environmentally sustainable street lighting. The Sierra Club believes our suggested revisions to the RFP are consistent with the DC Sustainability Plan and will help make the District a national model for safe, healthy, environmentally sustainable street lighting.