The much-loved LED art installation on the cables of the Bay Bridge, the Bay Lights, will be re-illuminated Friday with a fair amount of fanfare planned for their return.

As we learned last month, tonight, March 20, is the official relighting of the Bay Lights on the Bay Bridge, though the light installation has been flickering on here and there in recent weeks as it underwent testing.

Artist Leo Villareal, who now has prominent installations in London, Tokyo, Frankfurt, Auckland, and on the top of New York City's newest skyscraper, the JP Morgan Chase Building, got his start making LED artworks for Burning Man, before being commissioned to light up the Bay Bridge in 2013.

"I think of The Bay Lights as a way of making invisible systems visible,” said Villareal in a statement. “The bridge is already full of rhythm, traffic, weather, motion, time — and the light responds to that complexity through abstraction. It’s not about decoration. It’s about revealing the pulse of its location."

The nonprofit Illuminate was formed to fund Villareal's project, and to fund its first return, which happened in 2016. The original installation of 25,000 LEDs was only meant to have a two-year lifespan, and due to a planned repainting of the bridge cables, the lights had to come down in March 2015. That second version of the Bay Lights, intended to last 10 years, went live in early 2016 and only made it to 2023, when again weather and wear had dimmed many of the LEDs, and the piece was again shut off and removed.

An $11 million fundraising drive by Illuminate got underway to not only replace the Bay Lights on the north side of the bridge, but to install the LEDs on both sides of the cables so that they could be seen from the south as well, with total of 50,000 LEDs all told. And 1,500 people and companies donated to the project this time, with the donations ranging from $2 up to $1 million, according to Illuminate.

As the Chronicle puts, once the Bay Lights are turned on again at 7:30 pm Friday, th "dancing lights will [again] turn a piece of workhorse infrastructure into an Instagram-worthy tableau."

But the 25,000 little lights facing south won't be on tonight, because, as we learned, they will only go live "following completion of final safety testing and agency review."

"The Bay Lights are an iconic symbol of San Francisco and the entire Bay Area,” said Mayor Daniel Lurie at the time of the relighting announcement last month. “I’m thrilled to welcome back the light installation that will once again bring beauty and pride to our city and the whole region.”

Lurie will be on hand giving a speech at the relighting ceremony on the Embarcadero this evening — and tonight's celebration will also be honoring the 92nd birthday of former Willie Brown, who is the namesake of the western span of the Bay Bridge.

Multiple restaurants on the waterfront are hosting their own parties Friday night for the relighting. And the official after-party fundraiser is happening at SHACK15 in the Ferry Building — with tickets going for $200.

The new installation, dubbed Bay Lights 360, is expected to last for ten years.

Ben Davis, founder of Illuminate, says, "For the next decade, more than 20 million residents and visitors each year will find comfort, awe, and perhaps a little reassurance in that glow."