In the next 30 years, Sydney's population is set to nearly double and hit 8 million people.

But will we be able to cope?

"We will struggle," according to urban planner Sue Holliday, "unless we make some very big decisions soon ... about how we want to live in the future."

Ms Holliday is the former NSW director general of urban planning, a member of the Hume Community Housing Association in western Sydney, and was involved in the redevelopment of Ultimo, Pyrmont and Sydney Olympic Park.

As politicians, experts and think-tanks try and find solutions, Ms Holliday said the most important aspect to prioritise was how to maintain high quality of life.

That quality of life, she said, depended on good transport and housing affordability.

"I always ask the question, 'Does Sydney work for you?'," Ms Holliday said.

"Most often people say, 'I love Sydney but I can't get around', or 'I spend too much time travelling to work'.

"When you compare our city to international examples, we're not as equipped from an infrastructure example."

This week ABC Radio Sydney has been exploring the changing face of our city.

There have been conversations about space and where the projected extra 4 million people will live, the cost of living in Sydney based on coffee prices, access to rent controlled apartments, and how to keep power bills down as temperatures and urban development goes up.

Give people a choice

Ms Holliday said federal and state governments needed to "shift priorities" as other international cities had done to give people more transport choices.

There are suburbs in Sydney which do not have any access to sufficient public transport. ( ABC Radio Sydney: Amanda Hoh )

While she applauded the NSW Government for its investment in new metro lines and improving bus services, she said "it's not enough".

"There are parts of Sydney that just don't have public transport access ... and they're still talking too much about building more roads.

"There are whole areas of Sydney that are just not connected.

"To keep our quality of life, we need to give people a choice: 'Do I get in my car, or can I jump on public transport that will take me to where I want to go?'"

Given Sydney's sprawling metropolis, Ms Holliday said we needed to make the different regions across Sydney more self-contained with public transport and cycleways.

Rather than just focusing on travel across the city, she suggested government needed to support transport options within the suburbs and in regions outside the CBD.

Chris Pettit, professor of urban science at the UNSW City Futures Research Centre, agreed and said urban planning needed to focus on creating the "30-minute city" by helping people live close to their employment.

The benchmark for that lies in Blacktown where 75 per cent of people working in the suburb spend 30 minutes or less commuting there.

At peak hour in Blacktown, 75 per cent of commuters travel 30 minutes or less to get to work. ( Supplied: CityViz / City Futures Research Centre UNSW )

"As western Sydney grows, and areas like Blacktown plan to have an extra 60,000 houses, we need to use this [data] to measure performance in our city," Dr Pettit said.

"We need to ideally go back in five years' time and those metrics should stay the same or get better.

"It's all about making sure our quality of life doesn't go down."

Ms Holliday said creating cycleways to help people better commute within suburbs, such as Blacktown or Penrith, would get cars off the roads and improve liveability.

Amsterdam has made cycling the priority mode of transport for commuters. ( Wikimedia: AirBete )

Other cities to learn from

To build a more efficient city, Sydney needed to take inspiration from cities that had been well designed and planned, Ms Holliday said.

Los Angeles: While LA has a reputation of being a freeway city, the government has shifted it to be a city investing in public transport. It has introduced a metro and public transport to access a range of communities.

Bogata: This South American city is poor but it hasn't stopped it from building more public transport. Instead of freeways, they have busways or bus-only roads that link different parts of the city including the poorer parts. To get people up to the hills, they have built ski lifts at the end of the busways.

Vancouver: Vancouver is well known for achieving higher density with good street design experience. Townhouses are built at street level while towers sit behind. It was a concept adopted in the design of Pyrmont. Vancouver also prides itself on community engagement where residents all agreed on parts of the city which should be made higher density, while others are kept more suburban and lower density.

Amsterdam and Copenhagen: Much can be learnt from European city designs that prioritise active transport and encourage walking and cycling. While there are still cars on the road, these cities make using your bicycle to go to the shops, head to work or school easy and thereby people's first choice for their mode of transport.

"It's not about lycra," Ms Holliday said.

"It's about getting ordinary people to hop on an ordinary bike."