Is Auckland's congestion answer underground?

Auckland may be sitting on the underground answer to at least some of its transport woes.

Albert Park in the centre of the city is riddled with former World War II air raid tunnels. On Wednesday, the Auckland Council heard how they could be used to benefit transport and tourism.

It took 114 men just eight months to dig out three and half kilometres of tunnels as an air raid shelter.

But after World War II, they were filled with more than eight million clay blocks, to ensure the tunnels wouldn't collapse, and then sealed.

Bill Reid has dug out a small portion of one of the tunnels and has spent the past three decades trying to convince council to reopen the rest.

"It's 71 years since the tunnels were close… it should've been opened years ago. Then wasn't the climate - now is the tourist climate in New Zealand and Auckland."

The idea would be to turn the main tunnel running between Victoria Street and Constitution Hill into a cycle and walkway - linking the CBD to Parnell.

The Stockholm Metro is being held up as an example of what it could look like. But, it wouldn't just be limited to transport.

The proposal includes retail spaces, turning the smaller tunnels into wine bars, cheese shops and perhaps most audaciously a glow-worm encounter. It would make it the largest tourist attraction in Auckland.

It's estimated to cost up to $20 million but the council is not asking for any ratepayer money. Instead, they will get private backers and charge an entrance fee to recoup costs."

For Mr Reid, bringing back to life the city's history and heritage would be reward for a lifetimes worth of work.