Peculiar Pittsburgh

Pittsburgh’s Sign of Light illuminates the challenges of using light as public art

Pittsburghers have a lot of questions about this mysterious billboard — and the energy it uses.

Sign of Light, a project of the Pittsburgh Cultural Trust.

Sign of Light, a project of the Pittsburgh Cultural Trust.

Courtesy of the Pittsburgh Cultural Trust
MJ Slaby

Maybe it catches your eye while you’re watching a baseball game at PNC Park or when you’re crossing the Roberto Clemente Bridge.

It’s the sign atop Penn Avenue Place, with blue and white triangles that seem to appear at random. Unlike other billboards, there are no words.

And many of you have questions.

The Incline reader Shane Culgan (who is married to The Incline’s Food and Culture Editor Rossilynne Culgan) asked about the sign for our Peculiar Pittsburgh series, where readers pose questions, and our staff investigates. He asked:

“What is the blue and white ‘billboard’ Downtown? It faces the Allegheny River, can be seen from PNC Park and appears to project random blue and white triangles.”

It was one of several questions posed about Downtown oddities, so our staff put it to readers to vote. More than 500 of you did and nearly half of the votes selected this questions. We also answered the second place question here.

Don’t worry if we didn’t answer your question yet, there’s still hope. And there’s still time to ask a question.

But the question about the sign — actually named the Sign of Light — was a popular one. Not just with Culgan and our readers, but with WESA listeners, too. Right before our voting round closed, WESA published an article about the sign and its quest to give an identity to the Cultural District. But Culgan still had questions about what he said sometimes looks like a “broken billboard”— specifically about the costs and the power.

So we kept investigating.

Light Sequence for Sign of Light.

Light Sequence for Sign of Light.

Courtesy of the Pittsburgh Cultural Trust

The Sign of Light

Commissioned by the Pittsburgh Cultural Trust and installed in 1999, the Sign of Light aims to define “the Cultural District in space and time.” It’s 20-feet by 40-feet and uses LEDs to create floating triangles that slowly rotate and change colors. The triangle is a nod to the Golden Triangle, of course.

Since the sign is owned by the Cultural Trust, its funding comes from the organization’s fundraising efforts, not public funds. Marc Fleming, the Trust’s vice president of marketing and communications, declined to provide more information about the project’s costs.

However, “because LED technology has come so far and and is so affordable, the operating costs are extremely low unless you are illuminating a vast area,” said Sallyann Kluz, director for the Office for Public Art located at the Greater Pittsburgh Arts Council. Kluz added that she doesn’t count a billboard as a vast area.

According to the Trust, the sign is powered by roughly 10,000 LED lights. By comparison, Flow on the Wood Street T Station uses 40,128 red LEDs, while Cell Phone Disco on Tito Way uses 2,034 LED lights.


The former Energy Flow installation on the Rachel Carson Bridge

Jasmine Goldband / The Incline

Light as art

Major concerns for light-based art are lifespan and maintenance, Kluz said. When art is made of stone or bronze, the plan is easier. But with light, there can be technological changes, as well as a need to replace the bulbs. That can decrease the lifespan of a project to 5 to 15 years max in some cases, she said.

And as with most art materials, using light goes “in and out of fashion,” Kluz said. She said lighted public art gained popularity in the ’60s, ’70s and ’80s. Inside the Steel Plaza T Station are two examples of lighted art from the 1980s — Improvisations for Pittsburgh (1984) and Rivers of Light (1984 and restored in 2015).

There was a resurgence in the late ’90s and early 2000s (around the same time Sign of Light was installed) when LEDs came out, she said. The cost-effective bulbs meant funders were less likely to say a lighted project was too expensive.

In some cases, Kluz said, artists are especially interested in energy-efficient options.

Take Energy Flow on the Rachel Carson Bridge for example — the LED lights were powered by wind turbines. Now gone from the bridge, elements of the work were used for a Downtown lighted project called Garrison Canal, seen below.