May 15, 2025
The hub-and-spoke street layout in Washington, D.C., that Pierre L'Enfant designed in 1791 has inspired urban planners in Detroit, Indianapolis, and beyond. Now, planners may once again look to the District for innovations in their networks of streetlights to improve visibility and lower municipal energy costs.
Last May, D.C. started to replace more than 75,000 streetlights with energy-efficient LEDs over just 14 months, "making our neighborhoods brighter, our streets safer, and our city more sustainable," says Sharon Kershbaum, director of the District Department of Transportation (DDOT). "This milestone highlights the power of innovation and collaboration."
Covering 68 square miles of streets, bike paths, alleys, and tunnels, the $309 million public-private partnership is considered "an unprecedented effort" by Mayor Muriel Bowser to modernize the entire streetlight network. Officials say the new lights are more dependable (repairs dropped by 49 percent) and use less energy (energy costs fell by 70 percent) than the ones they replaced. Based on these early results, the District expects the LEDs will eliminate 38,000 tons of greenhouse gas emissions annually.
The project is a key component of the District's Clean Energy DC plan to reduce these emissions and energy consumption while increasing renewable energy. The plan calls for cutting energy use citywide by 50 percent by 2032 and becoming carbon neutral by 2045.
Working with the community
Lighting affects the human body in many ways. Robyn Jackson Wells, LEED AP, a former DDOT project manager, says planners should not underestimate the amount of public outreach needed when starting a replacement program. "Residents need to be prepared for the magnitude in the change of lighting and fully understand its impacts," she says.
This nighttime photo from 2020, shot from the International Space Station, shows Washington, D.C. (left) before the LED conversion project, next to Baltimore, Maryland (right), which had already completed its own BMore Bright initiative. Photo courtesy of NASA.
Alese Ballard, a project manager with Plenary Americas who led the District's effort, agreed. Her firm managed the consortium that designed, financed, installed, and now maintains the assets. "It seemed so simple to convert lights," says Ballard, "but at that magnitude and that quantity, it is really a big exercise in logistics, planning, and coordination." The District's decision to keep the Art Deco light poles originally installed in the 1920s also meant that details of each pole — such as height, arm length, and foundation had to be factored into the conversions.
To get the public's buy-in, 46 advisory neighborhood commissions weighed in on the project. One sticking point was brightness, because some residents considered it too harsh. The original plan showed LEDs with a color temperature of 5,500 to 6,000 Kelvin, which would cast light that was too blue and bright, according to local members of DarkSky International, an advocacy group that works to limit light pollution. "Blue light causes more glow," says board member Milton Roney.
Limiting the color temperature to bright, warm light has multiple health benefits, experts say, including enhancing the body's ability to fight cancer and other diseases. It also supports the circadian rhythm — our internal clock that regulates sleep-wake cycles and other functions.
One of the project's most notable benefits is the ability to adjust lighting levels dynamically, ensuring uniformity on roadways while maximizing energy efficiency, Kershbaum says.
District officials acknowledged that the transition to LEDs required an adjustment period for residents. Some wanted less-bright lights, while others called for public surveys to see if the lights could be brighter elsewhere. With the new LEDs, the light levels can be adjusted remotely.
D.C. revised its lighting plans based on community input. Meetings with neighborhood groups and DarkSky led to assurances that most fixtures would be 2,700 Kelvin and all below 3,000 Kelvin. The National Capital Planning Commission (NCPC) also played a role in the streetlight plan's development, says Diane Sullivan, director of the current planning division, because NCPC was simultaneously developing its Monumental Core LED streetlight performance criteria. That plan regulates lighting profiles on streets around the Lincoln Memorial, Washington Monument, and other federal buildings. Sullivan notes that while NCPC's performance criteria do not apply to rural lands, "they are sensitive to special settings such as the National Mall and the waterfront, so aspects of the criteria could be appropriate" for other less densely populated places.
One unrealized goal of DDOT's project, however, was piggybacking Wi-Fi access onto the streetlight project in underserved neighborhoods. Officials say it was difficult to get agreements with telecommunications service providers, but the city's office of technology installed Wi-Fi access points at schools, recreation centers, and other public buildings to fill some of the gaps.
DCSL Conversion Dashboard map shows almost 75,000 completed conversions (yellow) throughout D.C.'s eight wards, with about 3,000 streetlight conversions remaining. Map courtesy of District Department of Transportation.
Berry Russom, a high-voltage electrician leader for the Architect of the Capitol, works on a streetlight. The city estimates converting light fixtures to LED will reduce greenhouse gas emissions by 38,000 tons annually. Photo courtesy of Architect of the Capitol.
Collaboration continues
The DC Smart Street Lighting Project was the District's first public-private partnership (P3), and included the design, construction, and 15 years of maintenance. At the time, it was considered the nation's largest urban street modernization project using the P3 model, which promotes collaboration between the private sector and a government entity on major infrastructure projects.
In addition to Plenary, participants included the Phoenix Infrastructure Group, a D.C.-based minority-owned investment and advisory firm that supported the District's sustainability mission by partially financing the project with "green" municipal bonds that cities use to pay for sustainable infrastructure. Other members of the partnership are ENGIE North America, the design and construction contractor, and EQUANS, brought onboard to manage the lighting assets for 15 years.
With years of longer-lasting LEDs ahead, District officials point proudly to their success. The project leveraged private-sector resources, created jobs, and provided skills training and benefits for "businesses and residents alike," Kershbaum says.
Meanwhile, Ballard believes there are opportunities to install LED technology anywhere. "I want to say that large cities would benefit more from it," she notes, "because of density in an urban environment."
But that doesn't mean it will go without incident. In March, DarkSky's Roney says he received a call from a D.C. resident complaining about teardrop-shaped fixtures throwing glare in all directions. He says the organization plans to survey the city with light meters in the coming months to determine how closely the light levels match up with recommendations from the American Association of State Highway and Transportation Officials.
"We still think the lights are too bright," Roney says. "It requires constant vigilance. You can have rules, but you need people to follow the rules."
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