Adelaide's Rundle Mall is toasting 40 years as the city's shopping, social and cultural heart.

It was September 1, 1976, when Premier Don Dunstan officially unveiled Rundle Mall as one of the first pedestrian-only streets in Australia.

The 528-metre-long strip was packed with South Australians and lavishly christened when the old fountain was filled with champagne.

"It was a long time ago that people started to urge that we have a place in the city really for people and not for motorcars, where in fact the life of the city could find a heart," Mr Dunstan told the crowd.

"It wasn't just going to be a shopping place, but where people could come and stroll, meet one another, enjoy an open-air activity, and at the same time, of course, go and purchase what they wanted to.

"So the promise, 'meet you at the mall'... will become a common thing for Adelaide people."

Cars drive along Rundle Street in Adelaide before the creation of Rundle Mall. ( Supplied: Rundle Mall )

Locals would eventually adopt the phrase "meet you at the Mall's Balls" — an affectionate reference to Bert Flugelmen's Spheres, an unparalleled landmark and piece of public art in the state.

Architect Ian Hannaford was tasked with designing the original Rundle Mall in the 1970s, which was no minor feat amid considerable controversy.

"It was an interesting time because there was a great amount of discord amongst the stakeholders — the key retailers had one view, the government had another view, the smaller retailers had a different view, and then there was taxi ranks and everything else," he said.

"Don Dunstan said ... we'd get drums across the street and it would be turned into a mall, whether people like it or not."

The project team travelled to Canada, Scotland and continental Europe seeking inspiration for the pedestrian thoroughfare.

"I went to some lengths to make it very human-scale, soft underfoot with a cobbled brick character in the paving, shady trees and plantings, and very comfortable seats," Mr Hannaford recalled.

Undated photo of pavers being laid in Adelaide's Rundle Mall. ( Supplied: Rundle Mall )

"It was all designed so people would psychologically feel that they were being looked after, it was human-scale and they liked being there — that was the secret."

Over the years Rundle Mall has had several facelifts, the most recent completed last year, as well as big changes including the construction of the Myer Centre in 1991, the closure of John Martins in 1998 and the arrival of more international retailers.

Mr Hannaford would not be drawn on whether he liked the current design choices, saying it was a different era and motives had changed.

He said a lot of the smaller retailers and specialty stores had either relocated to the suburbs or disappeared entirely.

"Personally I find the seats uncomfortable, and it's not person-driven like I think it ought to be."

Rundle Mall's general manager Amanda Grocock said the street had an enduring emotional connection with most South Australians.

"It is the place where we all met our friends by the Mall's Balls, or saw a favourite artist perform in that space," she said.

"I think we're heading into a really exciting chapter for Rundle Mall ... whether that be Adelaide City Council's significant investment in Gawler Place or the State Government's investment in the tram extension along North Terrace."

Today, the precinct boasts 700 retailers, 300 offices and 15 arcades and shopping centres.