LIGHT RAIL: Cable car passengers will be treated to a lightshow until mid-March, to coincide with a New Zealand Festival show at the Botanic Garden.

Cable car passengers are tripping the light fantastic, through a tunnel decorated with 40,000 shimmering, shape-shifting lights.

A psychedelic passage of twinkling colour was launched on the cable car route yesterday to coincide with Power Plant, a New Zealand Festival light show at the Botanic Garden.

Forty-thousand RGB pixels, or digitally controllable lights, are arranged in arches along the 100-metre-long tunnel ceiling, and are programmed into pulsing, morphing sequences.

Light artists Angus Muir and Alexandra Heaney spent five nights creating the artwork, working overnight to avoid disrupting the cable cars.

"It's in a very unique space, but we got there," Muir said.

"It's exciting, it's all about discovery. You're coming up the cable car and suddenly you're in this beautiful space. You get these beautiful reflections on the cable car, it's great."

An architect by training, Muir has been fascinated by lights since childhood, and staged his first fireworks show aged 13.

"There's just something magical about them.

"We still consider this architecture. It's dealing with space, it's just more temporary."

Wendy Lochore, of Porirua, and her Brisbane-based sister Kim Kelly were blown away by the tunnel of light yesterday.

"It's spellbinding. We'd buy another ride just to see it again," Miss Kelly said.

Contact Energy has sponsored the tunnel and will give a free return trip to any of its customers and their travelling companions.