When Australia’s First Lady leaves her family’s harbourside mansion every morning she doesn’t climb into a limo; instead she gets a train out to Parramatta, a western suburb of Sydney. Once there she isn’t cutting ribbons or standing behind her husband, prime minister Malcolm Turnbull; instead she’s fixing Sydney, a city with big problems that casual visitors rarely see. A former lord mayor, businesswoman and leading philanthropist, Lucy Turnbull is now the inaugural chair of the new Greater Sydney Commission. She’s the planning supremo for the city.

Her mode of transport underscores the challenges she faces in her new role. “Train – always get the train. It’s the only predictable way to get there.” Driving would risk getting stuck in heavy traffic; just ask those who crawl through it every day from the western suburbs to work in the cbd. They are known colloquially as “westies” but the unkinder term is “squinters”: they drive eastward into the rising sun and back into the setting sun at night.

That sort of day-destroying congestion is something that Turnbull and the Commission are grappling with as they try to reimagine a rapidly expanding but still liveable Sydney. “Any big city suffers from the classic symptoms of urbanism, which are congestion, traffic and low housing affordability,” she says.

These are the dilemmas that Turnbull is trying to solve as Sydney’s population surges from its current 4.6 million to a projected 6.2 million by 2036 and 8 million by 2056. Some have argued that Sydney is full and all migrants to Australia should be directed elsewhere; Turnbull diasgrees. “Sydney is full if you don’t plan well for the supply and diversity of housing,” she says. “Thinking that a city within a country with a very high rate of population growth is ‘full’ is not helpful.”

Parramatta is at the heart of Turnbull’s vision and she wants the world to know that there’s more to Sydney than the Harbour Bridge, Opera House and Bondi Beach. She talks about Parramatta as the Central City, with the harbour and its surroundings comprising an Eastern City and a third hub to the west around the planned airport at Badgery’s Creek. Within each of these hubs she would like to create “30-minute cities” offering schools, jobs, recreation and healthcare within a half-hour radius of a person’s home. That means less gridlock – and fewer squinters.

In some ways Turnbull thinks that Sydney needs to draw inspiration from its past, harking back to the 1870s when its population was surging and rows of terrace houses were built in inner-city suburbs such as Paddington, Glebe and Newtown. Those former workers’ houses now sell for millions of dollars in an overheated property market.

As our interview ends Turnbull heads off to prepare for a speech for Sydney’s movers and shakers, where she again enthuses about Parramatta. Yet she’s delivering her speech at the waterfront Pier One hotel, within spitting distance of the Harbour Bridge; shifting Sydney’s focus westward will be no small challenge.

Short of bridges and roads to get its car-crazy residents around, Abidjan is looking to the Ébrié lagoon on which it sits to cut journey times. It’s hoped that riverboats Kong and Agboville – built in Hamburg – will soothe the tempers of five million commuters. But all depends on travellers’ willingness to pay cfa500 (€0.80), three times the amount charged by the clunky ferries that intermittently cross the lagoon.

In Gironella, in Spain’s Catalonia region, residents in the old quarter at the top of a hill have long faced a struggle visiting their friends and family in the newer neighbourhoods down below. A 20-metre-high lift of brick, steel and glass, designed by architect Carles Enrich, has solved the problem. Attached to the cliff-side, the towering structure has ensured that every get-together is now a smoother ride.