Viewpoint: Citywide lighting plan has unresolved issues


Washington, D.C. as seen from space. (Photo courtesy of Scott Kelly via NASA)

The Current’s April 11 article on forthcoming changes to District street lights, as described by Judah Gluckman of the Office of Public and Private Partnerships (OP3), was welcome, but incomplete.

Our nonprofit, Restore Mass Ave., is restoring the tree landscape and historic look of one of the last “Grand Avenues” in the nation, the Embassy Row part of Massachusetts Avenue.

We welcome that Mr. Gluckman said: “residential streets will probably be set at 2700 Kelvin.” He was referring to the new Light Emitting Diode (LED) streetlights, which the city is installing to save power. LEDs are of different Kelvins – a measure of color temperature – or blue content – of light. Previous LED deployments in the city have been the blue-white “soccer field” lights of 4,000 and 5,000 Kelvin. The 2,700 Kelvin is considered a warmer white.

However, the article missed some big issues: lights for major roadways, the possibly dangerous glare of present LEDs, and overlighting the night sky.

First, what LED levels will be allowed on major routes? Our city is connected by a network of roadways which the District Department of Transportation (DDOT) calls “collector,” “arterial” and “local,” roads. Massachusetts Avenue, running more than seven miles across town, is an “arterial.” As in other cities, major high traffic streets are lit more than residential ones.

RMA strongly supports the efforts of the expert D.C. Street Light Task Force (STLF) which advocates a maximum 2,700 Kelvin LEDs for all streets. Eight ANCs and 13 civic groups representing more than 116,000 residents have passed resolutions supporting the STLF goal. Another push was made by residents of 2540 Mass Ave. apartments, who petitioned Ward 2 Council Member Jack Evans to support this goal.

The issue is urgent for Restore Mass Ave because DDOT could install new LEDs on Embassy Row this fall, setting a precedent for future LED lighting on major streets. An agency of DDOT, the Infrastructure Project Management Division (IPMD), plans a huge “rehabilitation” of the historic mile of Mass Ave from Dupont Circle out to Glover Bridge at Waterside Drive. This is the route where RMA has been growing elegant rows of trees and restoring historic landscape.

These plans for road-and-sidewalk replacement include 200 new LEDs, which may be 3,000 Kelvin. Presently, high-pressure sodium lights of 1,900-2,100 Kelvin bathe the architecture and trees in gentle amber light.

But why set an arbitrary level? The STLF has proposed a municipal lighting designer with experience in city-wide LED conversion and we agree. A great advantage of LEDs (besides saving power) is that they are tuneable. The District is overlit, according to two previous directors of the DDOT; the District’s image from NASA’s satellite photo confirms this.

Second, the present debate misses that District streets already have 4,700 LED lights of very blue-white 4,000 and 5,000 Kelvin. During a February streetlight tour organized by RMA, attendees saw that the Dupont area is littered with these.

The American Medical Association two years ago declared that the “disability glare” of intense blue-rich LED light “has serious implications for nighttime driving visibility.” These lights “decrease visual acuity, decreasing safety and creating a road hazard.” They can “have worse glare than conventional” streetlights.

Streetlight policy should advance the mayor’s goal that travelers in the city transportation system have zero fatalities or serious injuries by 2024, known as Vision Zero.

Third, the District’s city streetlight conversion could lessen uplighting from the city at night. It could help public views of the night sky and stars and astronomy. Along the two miles where our group plants large-type trees and improves civic views, the largest property is the U.S. Naval Observatory.

We will promote the International Dark Sky Association’s recommendations that all city lights have “full cut-off shielding,”use only the amount of light needed, turn off when not in use, and the lowest color temperatures practicable.

A Grand Avenue is an ensemble of views of historic facades, framed by shapely trees, fragrant and fresh air, and lit appropriately for thousands of people after dark. By example along Embassy Row, Restore Mass Ave hopes to promote the best light policy city wide, so even more people will enjoy the District’s lovely thoroughfares and see more stars.

Deborah Shapley, President, Restore Mass Ave