To solve its traffic congestion problems, Sydney is digging deep.

Few people will ever argue that an urban road is a thing of beauty, particularly when it is filled with the glint and growl of slow-moving traffic. But encase that road underground, in a tunnel, and it becomes something else altogether. It is an engineering marvel, an unimpeded way to get from A to B as quickly and easily as possible, and a way to give back open space to the communities above, rather than take it away.

That is what WestConnex in Sydney is now aiming to do. Having already widened the M4 between Parramatta and Homebush, releasing thousands of motorists from a chain of 28 sets of traffic lights on Parramatta Road, it is now digging downwards. The new project extends the M4 at Haberfield in the inner west, via twin underground tunnels around 7.5 kilometres in length, with the M5 at St Peters, near Sydney Airport.

Australia’s largest transport infrastructure project, the WestConnex initiative is coming in at a reported cost of around $16.8 billion. It is expected to be open to traffic in early 2020, with the main tunnel open in 2023. The tunnel linking M4 and M5 has a project cost of $7.247 billion.

Once complete, this massive infrastructure build will result in 33 kilometres (14 kilometres above ground and 19 kilometres underground) of new motorway linking western and south-western Sydney to the city and airport. It is predicted that travel times from Parramatta to Sydney Airport will be cut by up to 40 minutes, bus travel times from the inner west to the city will be halved and up to 52 sets of traffic lights will be bypassed. Most impressively for residents, around 4000 trucks per day will head underground, rather than clogging up Parramatta Road.

It’s a big vision and a bold initiative, providing relief to the city of Sydney before traffic created chaos. Most impressive is the creation of green community spaces at the same time that trucks and other traffic are sent underground.

While road capacity will be doubled along the M5 East corridor, there should be no noticeable surface traffic increase. In fact, on the surface 10 hectares of disused Rozelle Rail Yards will become green space, reclaimed for the use of residents and including footpaths and cycleways. A new bridge is planned to link this space to other foreshore parks.

Another eight hectares of open space will be created, including six hectares in St Peters. These spaces, and the lesser transport times resulting from the better road systems, are expected to reduce greenhouse gas emissions by more than 610,000 tonnes per annum. Fourteen kilometres of new paths for pedestrians and cycles will become a reality. The entire project has/will create over 10,000 jobs, including 4,400 jobs on the New M5 project, 4500 jobs on the M4 East project and 900 jobs on the King Georges Road Interchange Upgrade.

“The M4-M5 link is part of a comprehensive range of road and public transport projects that are all connected and will make Sydney a much better place to live,” said Anthony Roberts, NSW Minister for Planning and Housing.

Such planning and progress is an essential to avoid an increasingly dysfunctional city, says Peter Newman, Professor of Sustainability at Curtin University and a speaker at Australian Engineering Conference 2018. Engineers, Newman says, play a key role in ensuring the sustainability of cities, particularly around transport infrastructure.

He is particularly interested in new technologies and innovations, such as ‘trackless trams’, convoys of driverless, electric buses that follow sensors down a road. “It’ll be the engineers who pick up on it,” Newman says. “They’ll team up with entrepreneurs, developers and good governments and we’ll get a new regime of building trackless tram systems through our cities that will solve many of our current problems.”

Good roads, good rail systems and innovation between the two, Newman says, will turn cities into places where home and work are always accessible within a 30-minute commute. The answer lies with a coming together of government and private commerce, as is the case with WestConnex. When that collaboration occurs, he says, anything is possible.

Learn more about the future of Australia’s transport infrastructure at the Australian Engineering Conference 17-19 September in Sydney. To register, click here.